ALBERT

Notes: Abstract. Populations of postlarval, juvenile and adult Kuruma prawns, Penaeus japonicus Bate, have been affected by an unusual proliferative condition of the midgut and ventral nerve cord. Animals affected with this gut and nerve syndrome have been observed from various shrimp systems in Hawaii, including high density tanks and raceways, low density ponds, and adult broodstock held in a maturation system. Affected shrimp ranged in age from ∼20-day-old postlarvae of ∼0.02g average weight to adult shrimp of ∼ 60 g average weight. The principal lesions observed in affected animals were a hypertrophy of the anterior midgut mucosal epithelium basement membrane (BM) and a hyperplasia of the epineurium that covers the ventral nerve cord and segmental ganglia in the gnathothorax. There seemed to be a positive correlation between increased thickness of the BM and disease, and possibly a relationship between ataxia and lethargy and the degree of hyperplasia of the epineurium.

Notes: Abstract. Two groups of rainbow trout fingerlings were exposed for 90 days to 0.2 and 0.4 mg/1 of un-ionized ammonia, respectively. Several fish exposed to the higher concentration soon developed clinical signs suggestive of a neurological dysfunction but subsequently recovered. No lesion attributable to ammonia was seen in the gills of any of the fish. This raises questions about the precise role of ammonia in the production of gill diseases in intensively cultured trout.

Notes: Abstract. Proliferative kidney disease (PKD) was diagnosed in rainbow trout, Salmo gairdneri Richardson, at the Hagerman, Idaho, State Fish Hatchery. Wild fish from Riley Creek, one of the hatchery water supplies, were infected with PKD organisms. Clinical signs, gross pathology and histopathology of affected fish were typical of those reported for PKD in salmonids from European hatcheries. In addition to lesions normally seen, we observed a severe vasculitis and occlusion of renal and hepatic vessels. Ultrastructure of the PKD organism and possible inclusion body production sites are described. The disease outbreak was complicated by the presence of other infectious diseases. This is the first recorded outbreak of PKD in North America.

Notes: Abstract. The efficacy of the immersion method of vaccination was evaluated using Aeromonas salmonicida bacterin. In general a 2 min immersion vaccination was not as effective as vaccination by intraperitoneal injection; however, the level of immunity was improved by giving multiple vaccinations several days apart. A primary immersion vaccination with bacterin diluted 1:4 followed by a secondary vaccination diluted 1:2 gave good results. The most concentrated secondary booster was more effective than boosting with more dilute bacterin.

Notes: Abstract. Epitheliocystis infections in the gills of carp from Israel and Portugal occurred in lining epithelial cells as well as mucus and chloride cells. Ultrastructural studies of infected cells revealed several morphological forms of epitheliocystis showing the existence of a pleomorphic developmental cycle. The following stages were observed: chlamydia-like round cells (RC), non-dividing round cells (NRC) and bullet-shaped small cells (SC). All these were identical in shape to RC and SC described from epitheliocystis of other fish, The rickettsia-like cells (PLC and ILC) which occur in epitheliocystis from other fish species and produce the SC were absent in carp epitheliocystis and instead the RC were seen transforming into SC. Transformation to SC, however, occurred at any stage of the developmental process, even before the replication potential of the RC was exhausted, i.e. before reaching the NRC stage.

Notes: Abstract. Mebendazole (methyl-5-benzoyl benziraidazole-2-carhamate) was shown to have anthelmintic activity against larvae of Proteocephalus ambloplitis (Leidy) in implantations were found to be highly effective. A single intraperitoneal injection of 200 mg/kg or a capsule implantation of 200 mg/kg of mebendazole each reduced the infection by 95 % after 6 weeks. Oral treatment for 14 consecutive days at 100 mg/kg/ day reduced I he infection by 90%. Intraperitoneal injection of 200 mg/kg of mebendazole ever, did not interfere with spawning and reproduction of largemouth bass; however fish injected with 300 mg/kg produced no fry. Haematocrit, total haemoglobin, total serum protein and histological changes were not evidenl in treated fish.

Notes: Abstract. Rainbow trout fed prepared rations containing therapeutic levels of erythromycin (110 mg/kg daily) developed lesions in epithelial cells of the first proximal segment of the nephron. Pathological changes which developed within 24 h were characteristic of congestive overloading of lysosomes. Treated fish became anorexic within 2–3 weeks. Affected epithelial cells offish after 14 days of anorexia contained residual bodies in an otherwise normal appearing cytoplasm. Cell injury was reversible. Since the onset of anorexia corresponded with the completion of the recommended treatment period and damaged cells repair rapidly, erythromycin should nevertheless be retained as the treatment of choice for bacterial kidney disease.

Notes: Abstract. The activity of the pituitary-gonad axis was examined in goldfish, Carassius auratus (L.), collected from two populations exhibiting epizootics of an ulcerative disease. One population, collected from a pond in Toronto, Ontario, exhibited a significant linear relationship between the extent of lesions and the ovarian state. In a second population, collected from Hamilton Harbour, Lake Ontario, there was no correlation between the high prevalence of oocyte atresia, or the ovarian state with the extent of the ulcerative lesions. Additionally, in the Hamilton Harbour population there were no seasonal changes in the stages of egg development, frequency of mature ova, activity of the pituitary-gonad axis or gonadosomatic index consistent with gamete release. This apparent spawning failure of the Hamilton Harbour population was supported by the age distribution in the population (no fish younger than 4 years of age were found), and probably accounts for the drastic decline in the capture success of goldfish at that site since 1978. This decline in capture success was correlated with the outbreak of a persistent epizootic of ulcerative disease, suggesting that either the lesions themselves caused the spawning failure, or that the spawning failure and lesion outbreak were both correlated with undetermined changes in the environment, possibly a deterioration in the water quality in Hamilton Harbour.

Notes: Abstract. A spontaneous unilateral exophthalmos occurring in five species of otherwise healthy rockfish, Sebastes spp., was investigated. All eyes from nine unilaterally exophthalmic and seven non-exophthalmic rockfish were examined grossly and histologically. In all affected fish the exophthalmos was due to enlargement of the globes resulting from the formation of choroidal cysts filled with a clear, watery fluid and surrounded by dense, aberrant connective tissue. Cyst formation led to gross distortion and disorganization of the choroid. Distorted remnants of the choroidal rete mirabile contained markedly fewer erythrocytes, a homogeneous proteinaceous material and a mild inflammatory cell infiltrate. Thickened scleral cartilage with disoriented chondrocytes was also present in exophthalmic eyes. Some of the affected eyes showed pigmentary abnormalities with clumps of heavily pigmented cells present in the retina and choroid. Retinal degeneration and detachment was also evident in some of the affected eyes.

Notes: Abstract. The histopathology of an atypical Aeromonas salmonicida found in Atlantic cod, Gadus morhua L., is described. Unlike members of the Salmonidae, the cod showed a well-developed host reaction to A. salmonicida involving encystment of the bacteria. When Atlantic salmon, Salmo salar L., were given an intramuscular injection with suspensions of cultures of this strain of A. salmonicida no cellular host reaction was observed. When cod were given a similar injection the bacteria showed degenerative changes, leucocytes accumulated, and cyst formation was seen in the spleen and kidney. Since cod can be infected by this organism the possibility exists that they could act as carriers, a source of infection for salmonids in saltwater cage culture or in the wild.

Notes: Abstract. Perfusion fixation of trout kidney with picric-acid: formaldehyde: acetic acid: ethanol mixture was compared with other methods as a fixative for staining with the alcian-blue PAS technique. Perfusion fixation gave conspicuously better results for light microscopical purposes.

Notes: Abstract. Experimental infection of artificially-induced skin ulcers in rainbow trout Salmo gairdneri Richardson with an achromogenic strain of Aeromonas salmonicida induced a syndrome similar to that observed in cyprinid fishes. Sequential histological observations showed that the presence of the bacteria completely inhibited any migration of peripheral epidermal cells and subsequent under-running of the ulcer resulted in its expansion, as peripheral epidermis sloughed.

Notes: Abstract. Since 1977, repeated outbreaks of infestation by Amyloodinium ocellatum (Dinoflagellida) in cultured gilthead bream Sparus aurata L. and seabass Dicen-trarchus labrax (L.) resulted in sporadic and mass mortalities. Fingerlings and yearlings as well as breeders were affected and, since 1978, larval and post-larval S. aurata in the hatchery. Infestations in juvenile and breeder fish were located predominantly on the gills and mucosal integument but in larval fish only the skin rather than the gills was infested. Histopathological changes of the infested gills are described. Vacuolar degeneration of the cells penetrated by the parasites’ rhizoids was evident at the site of attachment and cloudy swelling was apparent in the surrounding epithelial cells. In heavy infestations the entire epithelium of the gill filaments underwent hyperplasia with consequent fusion of the lamellae. Where hyperplasia was extensive the cells gradually degenerated while the inner epithelial layer showed distinct spongiosis and in some cases completely disintegrated. All heavily infested gills lacked mucous cells.

Notes: Abstract. Virus was isolated from the brain and pancreatic tissues of Atlantic menhaden with ‘spinning’ disease. The biological, physical and chemical properties of the isolate were similar to those of infectious pancreatic necrosis virus. Inoculation of the virus into healthy menhaden resulted in the characteristic signs and mortality associated with the natural disease.

Notes: Abstract. The process of the localization of bovine serum albumin (BSA) within the lymphoid tissues of the plaice is described. The spleen is seen to be of particular importance. Antigen is held, probably as an immune complex, in an extracellular position associated with the metalophil reticular fibres present mainly in the ellipsoid walls and scattered throughout the peri-ellipsoid areas and the melano-macrophage centres. In the kidney tissue, antigen was present mainly intracellularly within the reticulo-endothelial system (RES) and free macrophages. The extracellular antigen within the spleen persisted the longest (at least 37 days). Localization of BSA differed markedly from colloidal carbon in that the metalophil fibres of the ellipsoids and to a small extent those of melano-macrophage centres, are the site of BSA localization and not, as with carbon, macrophages which aggregate within melano-macrophage centres. The thymus and RES of the atrium of the heart played no part in uptake of BSA. The significance of antigen-trapping in vertebrates is discussed and the possible analogous function of the ellipsoid system in fish and germinal centres of higher vertebrates is considered.

Notes: Book reviewed in this article: Seawater Aquariums: The Captive Environment. By S. Spotte. Fish Cultivation in Sewage Stabilization Pond Effluent. By P. Edwards The Use and Potential of Aquatic Species for Wastewater Treatment. Publication No. 65. Appendix B. The Environmental Requirements of Fish. By J. Colt, S. Mitchell, G. Tchobanoglais & A. Knight. Marine Maladies? Worms, Germs and Other Symbionts from the Northern Gulf of Mexico. By R. M. Overstreet

Notes: Books reviewed in this article:Theory and Management of Tropical Fisheries. Ed. by D. Pauly & G. I. Murphy.

Notes: Abstract. A vacuum degassing apparatus was used to subject channel catfish Ictalurus punctatus (Rafinesque) to sublethal hypoxia for 24, 48 or 72 h. Spleen, liver, gills, anterior kidney and posterior kidney from the catfish exhibited histopathological changes that included necrosis, hyperaemia, oedema, haemorrhage, hyperplasia and hypertrophy. Of the organs examined, gills were most affected by the hypoxic conditions. After 5 days of reacclimatization to normoxic conditions, channel catfish continued to exhibit histopathological effects of prolonged hypoxia.

Notes: Book reviewed in this article: Sea microbes. By J. M. Siebueth. Farming the flat oysters of the genus Ostrea. By P. Korringa. Animal Tissue Techniques. By G. L. Humason. 4th Edn. Reef Fishes of the Sea of Cortez: The Rocky-Shore Fishes of the Gulf of California. By D. A. Thomson, L. T. Findley and A. N. Kerstitch. Tissues and Organs Text-Atlas of Scanning Electron Microscopy. By R. G. Kessel and R. H. Kardon.

Notes: Abstract. Pleistophora typicalis Gurley, 1893, a parasite of the striated muscle of Myoxocephalus scorpius has been re-examined at light- and electron-microscope levels. Foci of infection were almost exclusively found in the ventral body wall where a mixture of schizonts, sporonts and masses of pansporoblasts lay in direct contact with unaltered host myofibrils and mitochondria.All stages were surrounded by a thick (0-5 μm) amorphous coat, external to the plasmalemma. In schizonts this was traversed by channels passing from the plasma-lemma to a layer of vesicles in contact with the muscle. This coat became modified as a pansporoblast envelope surrounding the mature spores: at first a layer of fine granules was laid down about mid-way across the previously amorphous coat, while the channels disappeared. At the time when the sporogonial plasmodium retracted away from the coat to produce the pansporoblast cavity, the layer of the coat within the granules disintegrated into spherical vesicles. The pansporoblast envelope around the mature spores was composed of two or three layers of different electron density, including one which was strongly electron dense. The pansporoblast envelope as defined here corresponds in function, but not necessarily in origin, to the sporophorous vesicle that encloses the spores in other pansporoblastic microsporidia.Schizonts had an extensive system of smooth endoplasmic reticulum, composed of expanded vesicles and divided by plasmotomy into smaller multinucleate segments. The endoplasmic reticulum of sporogonial stages was comprised of a network of fine channels, parallel arrays of flat cysternae and close-packed stacks of membranes. The sporogonial plasmodium divided stepwise through smaller multinucleate segments into uninucleate sporoblasts. Nuclei were isolated throughout development.Two types of sporonts were recognized: large sporonts gave rise to pansporoblasts containing up to 200 microspores. Macrospore pansporoblasts always contained eight macrospores. Microspores measured 4–4 × 2·3 μm (fresh) and were probably uninucleate. Macrospores measured 7·5 × 3·0 μm (fresh) and were probably binucleate.Another microsporidium, found in the muscles of Blennius pholis, which had been attributed to the same species by Thélohan (1895), was distinguished on the basis of spore size (microspores 3·9 × 2·3 μm and macrospores 7·7 × 3·8 μm fresh) and by the fact that electron dense components were laid down in the pansporoblast wall early in sporogony. The species was named Pleistophora littoralis n.sp.

Notes: Abstract. A bacterium resembling Aeromonas salmonicida and determined to be the aetiologic agent of a cutaneous ulcerative disease in goldfish Carassius auratus (L.) was further characterized in this study.Forty-five isolates of the bacterium (43 from the United States and one each position (moles % guanine plus cytosine) and DNA homology. The bacteriological atypical A. salmonicida previously described. Several important biochemical characteristics distinguished the goldfish isolates from typical A. salmanicida, but the DNA binding experiments indicated a high degree of relatedness between the goldfish isolates and typical A. salmonicida strains.

Notes: Abstract. New methods were studied for the control of Ichthyophthirius muttifiliis Fouquet, one of the most serious parasites of fish. Totals of 272 fish, 354 I. Multifiliis trophozoites and 562,500 tomites were used in the screening of amprolium, ronidizole, and silver nitrate for parasite control. In addition, 1,465 trophozoites and 600 tomites were subjected to pulsed DC electrotherapy trials. Silver nitrate at 0·67 ppm was 100% effective in eradicating tomites, while ronidizole at 750 ppm gave 100% and 97% control of trophozoites and tomites, respectively. Amprolium and electrotherapy were both ineffective against trophozoites and tomites. Silver nitrate has promise as a safe and effective alternative to chemicals currently used to control I. multifiliis.

Notes: Abstract. The prevalence and pathology of the pseudophyllidean cestode, Polyonchobothrium clarias in the gastrointestinal tract of the teleost, Clarias mossambi-cus have been studied. The cestodes were most abundant in the gall bladder where they caused pronounced nodular outgrowths in the mucosa and exhibited a gradual decrease in number distally towards the rectum. Generally the intensity of the infection due to P. clarias was higher in young fish than in old fish.

Notes: Book reviewed in this article: Aquaculture-Institute of Biology Studies in Biology No. 106. By P. J. Reay. Immunity in Evolution. By J. J. Marchalonis

Notes: Books reviewed in this article:Advances in Aquaculture. Papers presented at the FAO Technical Conference on Aquaculture, Kyoto, Japan, 26th May-2nd June 1976. Ed. by T. V. R. Pillav & W. A. Dill.Methods for Assessment of Fish Production in Fresh Waters. Ed. by T. B. Bagenal.

Notes: Abstract. Ultrastructural observations on a possible aetiological agent and tissue changes in a previously described disease of hatchery reared larval oysters Crassostrea gigas Thünberg are reported. Spherical bodies, implicated in gastro-intestinal impaction, show a strong resemblance to the marine fungus, Hyalochlorella marina. Similarities include a thick outer wall structure, plate-like mitochondria and dense cytoplasm with small vacuoles.The dense fascicular masses, previously observed histologically at epithelial surfaces, consist of accumulations of irregular electron opaque bodies. Large accumulations of these bodies appear to exacerbate tissue damage and prevent normal velar function. In comparison with the reported virus-like particles in this disease, these dense inclusions and associated lesions are more frequently observed and thus seem to be more important in the disease process.Notes on normal epithelial surfaces of larval Crassostrea spp. are included.

Notes: Abstract. Sphaerospora angulata Fujita, 1912, has been identified as a frequent renal parasite of cultured carp populations in Hungary. Its prevalence ranged from 10 to 50% in the pond farms surveyed. The youngest carp infected were 21/2–3 months old. Infections were not common in one-summer fish and tended to become less frequent with increasing age of the host.The developing stages of S. angulata are found in the contorted tubules of the trunk-kidney but never invade the parenchymal tissue of the trunk or head-kidneys. The pansporoblasts developing in the wide proximal segment of the renal tubules, and the spores arising from the pansporoblasts are typically coelozoic parasites, for they apparently do not damage the tubular lining epithelium, nor its brush border. The main adverse effect of S. angulata is probably depression of resistance owing partly to deprivation of the host of nutrients secreted by the glomeruli and partly to mechanical obstruction of the distal tubular segments.

Notes: Abstract. Viral haemorrhagic septicaemia (VHS) is reported for the first time in sea-water cultured rainbow trout. Heavy mortalities with typical signs and lesions A VHS virus (serotype 1) was isolated from the diseased fish. The mortalities were caused only by the VHS virus and 80 days post transfer of trout to sea-water the mortalities reached 85%, of the initial population.The disease was experimentally transmitted to rainbow trout, both in sea-water 3·104 pfu/ml of virus or by intramuscular injection of various doses of VHS1 (7·101 7·104 or 7·104 pfu per fish). Death occurred in all infected groups and started earlier in sea-water. Typical signs of VHS were observed in moribund fish. Viral multiplication was demonstrated to have occurred in fish organs.

Notes: Abstract. Blood spots in the eye and haemorrhages in the musculature of the caudal peduncle were the main indication of disease in Australian hatchery reared brook trout Salvelinus fontinalis (Mitchill) and Atlantic salmon Salmo salar L. Mortalities of 0·1-0·5% per day occurred for 3–4 weeks in fish stocked in circular ponds in the months of February and March when temperatures were falling from 23–11·C. The bacterium belonging to the Family Enterobacteriaceae had similarities with Yersinia ruckeri (the RM bacterium) and Serratia liquefaciens. As a temporary designation SBS was used. It is recommended that its taxonomic position remain sub judice for the present. Inoculation experiments on brook trout and landlocked Atlantic salmon indicated that signs appeared 2–7 days after inoculation and that rainbow trout Salmo gairdneri Richardson were resistant to the disease.

Notes: Abstract. Giemsa stained blood smears prepared from blennies caught on the shores of southern England and from cod taken from the Celtic and North seas revealed fish with clinical ‘piscine erythrocytic necrosis’ (PEN). The findings recorded here extend the distribution data on PEN infections and report that the infection in the blenny and cod may possibly have a similar developmental pattern. Data are presented on the prevalence of the infection in the fish population samples and on the proportion of infected cells in the smears examined.

Notes: Abstract. This paper reports for the first time the application of the direct negative staining technique for the rapid confirmation of the viral nature of blenny‘piscine erythrocytic necrosis (PEN). The virus in negatively stained preparations has an internal core structure which appears in exact opposite contrast to that seen in thin sectioned virus. The resultant images from both negative staining and thin sectioning suggest that the organization of the core is unique amongst intracytoplasmic deoxyriboviruses (ICDVs).

Notes: Abstract. Electron microscopical and histopathological investigations were carried out on the anterior kidney often 1-year-old farmed rainbow trout naturally infected with the external signs of viral haemorrhagic septicaemia (VHS). The histopathology of the liver and the haematology of peripheral blood were also examined. The presumptive virus of VHS was directly demonstrated for the first time in the anterior kidney.All diseased fishes showed necrotic changes in the kidney and the liver. The melano-macrophage centres of the anterior kidney showed a partial destruction accompanied with a loss of melanin. A progressive destruction of the erythrocytes was observed. The liver exhibited moderate to extensive necrosis (karyorrhexis and karyolysis with lymphocytic invasion in the necrotic areas). Neither intranuclear nor intracytoplasmatic inclusions were observed. In the peripheral blood diverse stages of erythrocytic degeneration, amitoses of the erythrocytes and a five-fold increase in lymphocyte numbers were observed.

Notes: Books reviewed in this article:Tilapia—A guide to their biology and culture in Africa. By J. D. Balarin, assisted by J. P. Hatton.Pathophysiology—Altered regulatory mechanisms in disease 2nd ed. Ed. by E. D. Fkohuch.

Notes: A new method of determining fish numbers in a large river, which involved electrofishing from boats downstream to an AC electrical barrier, produced capture efficiencies for different species ranging from 28 to 82% when successive pairs of catches were combined. Estimates of population density, biomass and production for the 18 species in a 2.538 ha segment of the Pilica River, Poland revealed a decline in total numbers of the fish in species diversity between 1963 and 1980. This is attributed to increased fishing pressure, and to a loss in habitat diversity following the loss of many water mills and associated dams. The total production estimate of 0.85 g m−2 year−1 is low compared with the few published estimates for other large rivers. Roach, dace, chub, gudgeon and bream were the most numerous fish and they constituted 75% of the total population estimate, and 68% of the standing crop and annual production.

Notes: Every year from 1939 to 1982 autumn-spawning charr, Salvelinus alpinus L., have been monitored in the north basin of Lake Windermere. Gillnets of mesh 32 mm bar were used. Up to 1974 the nets were set in Low Wray Bay, but, because of interference by the public, from 1975 they have been set at Thompson Holme, a less accessible site. The results from the two sites are not directly comparable. The main spawning time is November, and catch per unit effort (net day) in November has been calculated. From 1944 to 1974 the catch per unit effort showed an increasing trend, and from 1975 to 1982 it has been relatively stable. Growth was similar in the 1940s and 1970s. It is suggested that the increase in numbers of charr could be due to reduced predation by pike.

Notes: Densities of salmon, trout and grayling were assessed in Scottish streams by systematic counting by underwater observers, where the water was greater than 1 m deep, and by using electrofishing equipment in adjacent shallower areas. Tests of the efficiencies of the two methods are described. Applications have included the estimation of production of trout, grayling and young salmon at a site on the River Tay and predicting the salmon smolt run of the River Tilt, and these applications are briefly described. The most suitable period for visual counting was summer, as at water temperatures of less than 15° C fish were hiding among stones in the stream bed. Wet weather hampered both electrofishing and visual counting.

Notes: Large variations in the number of female adult salmon spawning in the Girnock Burn each year (range 28–127) produced smaller variations each year (range 2900–5600) in the number of juvenile migrants. The relative constancy of the parr migrations was achieved by changes in their age composition. There may be no advantage in allowing ova deposition to exceed a level around 200 000 (3.4 m−2) in the Girnock Burn, which would give rise to an average of about 4000 juvenile migrants (0.07 m−2) per season. Large numbers of ova (up to 12.5 m−2) did not decrease the number of juvenile migrants.

Notes: Landlocked salmon derived from a wild population of stunted ouananiche and bred in the laboratory showed signs of smoltification, but adaptation to sea water was slow and limited to 11% of the fish tested. Sea water survival was not related to initial size, within the range used, nor to sex, age (2 + years v. 3 + years) or spawning history.Freshwater ouananiche had fewer gill chloride cells than anadromous smolts of similar size in fresh water. Anadromous smolts showed an increase in chloride cells after adaptation to sea water and those ouananiche which successfully adapted to sea water had a greatly increased number of gill chloride cells.

Notes: Fish mortalities in the River Nidelva, South Norway in 1978, were suspected to be caused by Gas Bubble Disease. In June 1980, the hydrological situation occumng in the Nidelva in 1978 was reconstructed, and the effects were analysed by keeping fish in cages. Examination of the dead fish showed that most were killed by Gas Bubble Disease. The results also showed that brown trout, Salmo trutta, was the least tolerant, and eel, Anguilla anguih, was the most tolerant to dissolved gas supersaturation. Only fish kept near the surface were killed while fish kept at 3 m depth were mildly affected due to hydrostatic pressure compensation. In contrast to the situation in 1978, few of the wild fish were killed during the experiment in 1980.

Notes: Cichlasoma nigrofasciatum, the convict cichlid, is a biparental, substrate-spawning, Central American cichlid. Male-female pairs were kept for 4 months on one of three food rations: high–1 g food daily; medium–1 g three times per week; low–1 g per week. The number of spawnings was directly related to the food ration. The fecundity of the females on the low and medium rations declined. At all rations the inter-spawning interval and egg size increased during the experiment. Egg size was positively related to ration and the length of the inter-spawning interval, but the latter was inversely related to ration. Females on the high ration grew in weight while those on the low ration lost weight. Histological examination of the ovaries at the end of the experiment suggested that low rations reduced the proportion of oocytes that become vitellogenic. At the end of the experiment, the total, gonad and liver weight of females at a given length were significantly related to ration. No similar, significant effect was found for the males, although growth in length of the males was related to ration. Ration had no detectable effect on the histological appearance of the testes.

Notes: Fish were sampled by electrofishing at three contiguous sites 26 km from the source of Oued Sebaou, a seasonal river in North Algeria. River discharge ranges from 300 m3s−1 in the peak of the rainy season to 0.1 m3s−1 at the end of the dry season. Extensive gravel extraction from the river bed takes place during the dry season.Two species were recorded at each site: Barbus callensis, which is heavily fished locally, and Anguilla anguilla. The three sample maximum likelihood Zippin method was used to estimate mean density and standing crops, which were: barbel, 452 fish ha−1, 5.33 kg ha−1; eels, 149 fish ha−1, 3.04 kg ha−1. Estimated average biomass and production were: barbel, 2.31 kg ha−1, 4.27 kg ha−1 year−1; eels, 1.51 kg ha−1, 2.60 kg ha−1 year−1.

Notes: Changes in the size and composition of a population of the acanthocephalan Acanthocephalus clavula in eels, Anguilla anguilla, and flounders, Platichthys flesus, its definitive hosts, in a small river are described over a period of 4.5 years in the course of which the population underwent a steady and continuous decline. Parasite prevalence and abundance declined more rapidly initially and then more gradually, and during the period the frequency distribution changed from overdispersed to being close to random on most occasions. Throughout the whole period newly recruited parasites were found in eels, and adult females continued to mature and produce acanthors. Data on the distribution and occurrence of the intermediate host Asellus meridianus in the river suggested that in the latter part of the decline it was no longer possible for the parasite to complete its life cycle in some parts of the river, and the cause of the parasite population decline is believed to be the decrease in abundance of the intermediate host as a result of interspecific competition with a congeneric species. During this latter period, immigration of infected eels from another river in the catchment may have contributed to the maintenance of the parasites in the locality, but it is considered that the decline in the river was representative of what was happening in other parts of the catchment and that the whole parasite population in the catchment was declining for the same reason.

Notes: The effects of capture stress, exposure to a hypo-osmotic environment and elevated water temperatures on the ascorbic acid (AsA) content of several mullet, Mugil cephalus, tissues were examined. All the treatments significantly altered tissue AsA levels, but the pattern of AsA fluctuations varied. Gill AsA concentrations increased two fold after exposure to a hypo-osmotic medium (salinity changed from 30‰ to 5‰), whereas AsA content in this tissue declined after capture. Both treatments depleted AsA reserves in the kidney. AsA concentrations in the brain increased after exposure to low salinity and elevated water temperatures, but were unaffected by capture stress. None of the treatments caused long term alteration of hepatic AsA reserves. Ascorbic acid inhibited oubain-sensitive Na+, K+-ATPase activity of gill tissue in vitro. The results suggest an involvement of AsA in osmo- or ion-regulatory functions of teleosts gills, salinity and thermal adaptation mechanisms in neural tissue, and the response of renal tissue to adverse environmental stimuli.

Notes: Changes in the seasonal development of the gonads in Acanthopagrus latus and A. cuvieri over an annual reproductive cycle are described. There is one major spawning period from January to March. Hermaphrodite A. latus and A. cuvieri constituted 5.8% and 5.7% of the total sample respectively. The histological changes in the ovary, testis and ovo-testis in both species are described. Fecundity estimates for A. latus, 27.5–31.8 cm, ranged from 1 362 137 to 2 152 993, and estimates for A. cuvieri, 47.1–63.5 cm, ranged from 308 273 to 1 693 365.

Notes: Triploid rainbow trout were produced by hydrostatic pressure applied to eggs 40 min after fertilization. Treatment for 10 min with or without exposure to 2% ether produced high hatching rates. Nuclear measurements from serial section of 40-day-old fry and from blood smears of 5-month-old juveniles showed that the proportion of triploid individuals was 80–90%. Ether treatment alone did not induce triploidy. Attempts to produce tetraploids by hydrostatic pressure treatment of eggs at 8 h after fertilization failed. Parallel results were also obtained with heat shock.

Notes: The stages in the life cycle of Bothriocephalus acheilognathi have been studied with the aid of scanning electron microscopy. Emergence of the coracidium occurred after 3–5 days at 20°C. Soon after hatching the coracidium began to swell and the cilia became coiled and lost their locomotory function. The surface of the coracidium was covered in protuberances of unknown function. After consumption by the copepod intermediate host, the coracidium developed into a procercoid. Upon development of a cercomer the procercoid could infect the fish definitive host. Identification of adult B. acheilognathi should be made on specimens relaxed in cold water for 10 min, and be based on the heart shaped scolex and prominent square apical disc.

Notes: Using spleen and head kidney imprints, studies on erythropoiesis in Channa punctalus have been made describing each developmental stage with regard to its morphology, morpho-metry and cytochemistry. This has been undertaken using the new techniques available for haematopoietic studies of fishes. These include autoradiography for information on DNA synthesis and Graham-Knoll's benzidine method with Giemsa used as a counterstain for the differential staining of haemoglobin. Thus, a more definitive picture of the haematopoietic phenomenon in Channa punctatus has been evolved.

Notes: Developing 1+ male Atlantic salmon parr were treated with methallibure and cyproterone acetate. Both these drugs failed to prevent gonad maturation but they did decrease the gonadotrophic cell size and lower plasma androgen levels. These results are discussed in relation to previous studies. It is concluded that gonadotrophic cells control gonadal androgen production, that cyproterone acetate is a central inhibitor of gonadotrophin production and that these two chemical agents could be effective as chemosterilants if administered early in gonad maturation cycle.

Notes: The food habits of the mudskipper, Pseudapocryptes dentatus (Val.) ranging from 43 to 205 mm in total length collected from the mudflats at Fao estuary, Iraq were studied. A combination of numerical, frequency occurrence and gravimetric methods was used to analyse the stomach contents, both qualitatively and quantitatively. The fish was found to be a strict herbivore and a frequent feeder. It fed solely on phytoplankton dominated by benthic forms. Diatoms were the most important food item in respect of both numerical and frequency occurrence methods comprising about 84% of the total number of phytoplankton organisms. The types of phytoplankton that contributed significantly to the diet were, in decreasing order of importance, Pleurosigma, Navicula, Nitzschia, Synedra, Closteriopsis and Oscillatoria. Larger fish had consumed lesser amount of food, and there was usually a gradual decrease in consumption with increase in size. The mudskipper consumed food ranging from 1·3 to 10·5% of its body weight.

Notes: The distribution, morphology and cytochemistry of the eosinophilic granule cells in the gut of the rainbow trout, Salmo gairdneri, were studied using light and electron microscopes. Granule cells were associated generally with the propria of the gut wall, the majority being arranged in a definitive layer, as a stratum granulosum. The cytoplasm of the eosinophilic granule cells contained numerous spherical, membrane-bound, homogeneous electron-dense granules, ranging from 0·1–1·3 urn in diameter. A portion of the cytoplasm located towards one pole of the cell was usually devoid of organelles other than ribosomes. Whatever their location, the eosinophilic granule cells were always associated with fixed connective tissue cells, referred to here as ‘ensheathing’ cells. Phospholipid, acid mucopoly-saccharide and the activities of alkaline phosphatase, acid phosphatase, arylsulphatase and 5-nucleotidase were demonstrated in the granules. It is hypothesized that the ‘ensheathing’ cells and eosinophilic granule cells constitute a part of the body defence mechanism.

Notes: Several aspects of salmonid sperm have been critically reviewed: structure, density, volume, chemical composition, metabolism, fertilisation techniques, motility, dilution, activation, storage at temperatures above and below 0deg; C and cryopreservation.

Notes: Light and electron microscopic examination of fathead minnow head kidneys revealed that the interrenal and chromaffin cells were intermingled and always closely associated with the cardinal veins and their tributaries. Histochemical tests for lipids in the interrenal cells were positive, and two types of chromaffin cells were indicated by chromaffin reactions. Interrenal cells contained abundant smooth endoplasmic reticulum and mitochondria with tubulo-vesicular cristae, characteristic of steroid-producing cells. Only one interrenal cell type was found. Two types of chromaffin cells were present with differences in cytoplasmic density and in types of granules. In light cells, adrenaline granules were most common, and in dark cells noradrenaline granules predominated.

Notes: The topological characteristics of the entire gut surface of the rainbow trout were investigated utilizing the scanning electron microscope. The mucosa exhibited longitudinal ridges in the oesophagus and stomach, villi in the intestine, fine longitudinal ridges in the caeca and annular folds in the rectum, arranged as a stack of caudally-directed funnels starting from the intestino-rectal valve to the vent. Detailed study revealed taste pores in the anterior oesophagus and the sculpting of the luminal plasmalemma of the surface cells into micro-ridges with complicated patterns. The surfaces of the posterior oesophagus and stomach were demarcated into polygons by rows of stubby microvilli—each polygon representing the luminal surface of an epithelial cell. Each rectal fold consisted of a smooth, caudally-directed apex and a base which was supported by perpendicular buttress-like secondary folds. The functional significance of these features which emphasize the vast difference in the physical length of the gut and the effective surface area is discussed.

Notes: The biology of a Scottish population of the small bothid flatfish, Arnoglossus laterna, was studied from January 1975 until September 1976. The data were taken from monthly samples totalling over 500 fish trawled in 18–36 m on a soft mud bottom. Otoliths were used for age determination and a growth curve was constructed which showed that most growth occurs in the first 2–3 years of life. The maximum age recorded was 8+ years. The fish first mature sexually in their second year at a standard length of 6–7 cm and the short spawning season lasts from the late June to August. Fecundity is length-dependent and the relationship could be described by the regression equation: log fecundity = 3·3472 log standard length (mm) -2·1064. The diet consists mainly of decapod crustaceans (particularly crangonid shrimps), polychaetes, mysids and small fish.

Notes: Books reivewed in this article.THE USE AND POTENTIAL OF AQUATIC SPECIES FOR WASTEWATER TREATMENT. THE ENVIRONMENTAL REQUIREMENTS OF FISH, by J. Colt, S. Mitchell, G.ATLANTIC SALMON. ITS FUTURE, edited by A. E. J. Went.TILAPIA: A GUIDE TO THEIR BIOLOGY AND CULTURE IN AFRICA, by John Dominic Balarin assisted by John P. Hatton.

Notes: The metazoan parasite fauna of two species of freshwater fishes Aplocheilus panchax and A. melastigma collected from a stream at Waltair is compared; 17 parasite species were found. Aplocheilus panchax served as a host to 13 parasite species and A. melastigma to 10 parasite species. Of the 17 parasites collected, 12 were larval helminths to which the fishes act as intermediate and paratenic hosts. This has been attributed to the interaction between terrestrial birds, mammals and fishes in determining the parasite fauna in the biocoenosis. The parasite fauna of these fishes is divided into typical and less typical according to their frequencies. Among less typical there are peripheral division parasites which are abundant in other fishes in the stream. Only six parasite species occurred in both A. panchax and A. melastigma and both fish shared most of their parasite fauna with other fishes. Differences in the parasite fauna of these fishes are attributed to the morphological, behavioural or ecological features of these fishes.

Notes: Methods for analysing fish stomach contents are listed and critically assessed with a view to their suitability for determining dietary importance—this term is defined. Difficulties in the application of these methods are discussed and, where appropriate, alternative approaches proposed. Modifications which have practical value are also considered. The necessity of linking measurements of dietary importance to stomach capacity is emphasized and the effects of differential digestion upon interpretation of stomach contents outlined. The best measure of dietary importance is proposed as one where both the amount and bulk of a food category are recorded.

Notes: Using a volume dependent model of evacuation, the effects of dietary energy level and source upon gastric emptying were examined. Diets containing small amounts of energy were evacuated from the stomach more rapidly than those with a higher energy content. When the data is examined with respect to the evacuation of energy from the stomach and is plotted as √Energy = ce−me Time; the rate of evacuation (me) is seen to be independent of energy level and the composition of the diet.

Notes: Abnormalities were detected in the testes of maturing male Atlantic salmon parr from one hatchery. They consisted of a focal necrosis of germ tissue at the time of rapid cell division when normal germ cells were reaching the spermatid stage of development. Some males taken from sea water which had matured previously in fresh water, had fibrous capsules in their testes as remnants of the freshwater lesion but there were no new abnormalities developing in the gonads. The same stock of fish showed other abnormalities and the authors speculate on a possible connection between these changes and the gonad lesion.

Notes: Laboratory studies on the thrce-spined stickleback provided predictive equations for the relationships between food consumption, faecal production and growth, and between respiration rate and body weight. These equations were used to estimate the energy income and expenditure at monthly intervals during the annual reproductive cycle of females of mean length from two populations. In winter only a small percentage of the energy income was invested in ovarian or somatic growth, and the latter was negative in some cases. Routine respiration and faecal losses accounted for a high proportion of the energy income. In spring a higher proportion of the energy income was partitioned into somatic and ovarian growth while routine respiration accounted for a smaller proportion of the energy income.

Notes: Before and after application of severe, debilitating stress, automated chemical analysis was applied to the skin mucus and the serum of four subsistence fish species: Chanos chanos, Mugil cephalus, Sarotherodon macrochir and S. mossambicus. Certain tests were found to reflect the stress effects. Future use of these tests may be on an individual, less expensive basis. Greater use of mucus for analysis is suggested because it is more accessible and less traumatically obtained than blood.

Notes: The numbers of chloride cells on the gills of three-spined sticklebacks, Gasterosteus aculeatus, have been measured after exposure of the fish to 0.5, 1.0 and 1.5 mg Cd2+ dm−3 soft water (132 mg dm−3 as CaCO3) and 2, 4 and 6 mg Cd2+ dm−3 hard water (299 mg dm−3). The numbers of chloride cells increased with time but later tended to decline. The significance of this finding is discussed in relation to the functions of chloride cells, one of which is presumed to be to eject absorbed heavy metals such as cadmium.

Notes: Book review in this article:FISH STOCK ASSESSMENT. A MANUAL OF BASIC METHODS, by J. A. Gulland.FROM YEAR TO YEAR: INTERANNUAL VARIABILITY OF ENVIRONMENT AND FISHERIES OF THE GULF OF ALASKA AND THE EASTERN BERING SEA. By Warren S. Wooster.

Notes: Scanning electron microscopy was used to examine the intestinal bulb and the caudal portion of the intestine proper of the goldfish, Carassius auratus. The observations made correlated well with previous light microscope studies by other investigators. The mucosal surface of the entire intestine of the goldfish is thrown up into folds, which are oriented along the long axis of the digestive tract in the intestinal bulb, but run more or less transversely in the caudal intestine. Tops of the folds were observed to be rounded or flattened, and the folds themselves formed wavy or zigzagging patterns in the mucosal surface. Numerous mucus-secreting goblet cells were seen, which were apparently more numerous or more active in the caudal intestine than in the intestinal bulb. The goblet cells are not uniformly distributed throughout the mucosa: they are more evident on the sides of the folds, although occasionally they appear to be located in clusters on the tips.The goblet cells were observed to contain varying amounts of mucous material, and/or to be of different sizes. Although no histochemical tests were performed, the possibility that digestive enzymes known to be present in the intestine may be elaborated by the goblet cells was considered, based on their variable appearance.

Notes: Crappie, Pomoxis annularis, from Lake Decatur, Illinois, were reported to have a high incidence of backbone deformities, an investigation was initiated to determine both the mechanism of vertebral injury and the causative agent. Three groups of fish were collected: normally shaped and abnormally shaped crappies from Lake Decatur and control fish from abnormally shaped crappies from Lake Decatur and control fish from nearby Lake Sangchris. Analysis of organic and inorganic residue levels in fish tissue revealed no significant levels of contaminants in any of the three groups. Evaluation of the mechanical properties, biochemical composition, and density characteristic of vertebral bone showed no significant difference between the three groups. A myxosporidean parasite, found in both normal and abnormally shaped crappies from Lake Decatur, may have been a contributing factor leading to the spinal deformities. We believe that a short-term exposure to organophosphate insecticides, may have occurred causing muscular contractions and resulting in vertebral damage and abnormally shaped fish.

Notes: The dynamics of increase of the predominant white muscle fibres of the myotomal bulk in bluntnose minnow, Pimephales notatus, ranging from 2.0 to 9.1 cm f.l. have been analysed by examination of modal progression of fibre diameter frequency classes in fish fed to satiation and growing at different rates at 15, 25 or 30°C. Recruitment of new fibres appeared to contribute little to increase in muscle bulk above 4 cm f.l., and nothing beyond 6 cm. The dominant means of increase was increase in fibre diameter. The limiting fibre diameter seemed to be 120 μ. These dynamics, which result in an approximately 1: 1 ratio between mean fibre diameter and f.l., are in contrast to those of the myotomal white muscle of rainbow trout, Salmo gairdneri, in which, regardless of differences in somatic growth produced by temperature, ration size or growth hormone administration, mean fibre diameter does not exceed that in bluntnose minnow until trout exceed 30 cm f.l. In trout there is, moreover, input of new fibres up to approximately 50 cm f.l., when subsequent growth, as in the minnow, is by means of fibre diameter increase. The bluntnose minnow is a small, slow growing species; the rainbow trout is a large, fast growing species. The discussion links these facts with the observed differences in fibre growth dynamics in relation to a hypothesis of interspecific differences in fish growth capability.

Notes: Samples of perch, Perca fluviatilis, were examined for the contents of their gastrointestinal tract and for the intestinal nematode Camallanus lacustris (Zoega). The seasonal dynamics, dispersal pattern and site preference of the nematode were studied. Both larvae and adult worms were present in the perch throughout the year. The abundance of C. lacustris was non-seasonal, but seasonal cycles were found in the numbers of larvae and of gravid females. C. lacustris showed a tendency to an increase in mean intensity with the size of perch. The frequency distribution of the nematode followed the negative binomial at different times of the year and in different length groups of perch. C. lacustris showed a seasonal site preference in the perch gut.

Notes: A progressive fall in serum thyroid hormone levels was found in Lake Ontario coho salmon, Oncorhynchus kisutch, between May 1978 and January 1979 concomitant with an increase in goitre frequency and thyroid hyperplasia. Despite marked differences in overt goitre frequency in sexually mature adult salmon collected from Lakes Ontario (43.7%), Erie (93.5%), or Michigan (0%), serum thyroid hormone levels and thyroid histology were similar in fish from the three lakes. Two gonadotrop-like basophil cells (‘globular’and‘vacuolar’) were found in the pituitary, particularly in sexually maturing and mature adults and‘jacks’. Whereas in salmon from Lakes Ontario or Michigan, the globular cells were vacuolated in Lake Erie salmon they were not; this observation may be correlated with the absence of obvious secondary sexual characteristics in Lake Erie salmon. Serum free fatty acids serum, triglycerides and cholesterol concentrations in Lake Ontario salmon fell progressively from the condition in fish collected from the Lake in May 1978, to that of fish collected during their potamodrous migration in November 1978 and January 1979.

Notes: The Kafue Floodplain fishery produces an annual fish yield of about 5000 tonnes. The 1971 closure of the Kafue Gorge Dam downstream from the floodplain modified flooding patterns. Pre-impoundment studies predicted this modification would increase fish stocks. Experimental gillnets set in 1975 and 1976 caught 18 species on a regular basis, nine of which were abundant enough for comparison with catches in similar gillnet samples taken prior to completion of the Kafue Gorge Dam. Of these nine species, experimental gillnet catches of three predator species were smaller in 1975–76 than in 1969–70. Catches of only one species increased significantly. Whether this change is due to the modified flooding pattern is unclear; unusually dry flood conditions in 1973 and increased fishing effort may have contributed.

Notes: Fish toxicity of etho-nonylphenol and of two non-ionic antifoam agents was tested using rainbow trout, Sulmo guirdneri, in 24 h tests. The surface tension of these three compounds was found to depend on concentration and ageing time of the test solutions. The toxicity of the surfactant was about twice as high as known values, with a LC50 of 8.5 mg/1 at 15°C. The addition of antifoam agents to the surfactant solutions further lowered the surface tension but did not alter substantially the fish toxicity of the surfactant. Contrary to expectation, the fish survived in concentrated antifoam solutions at surface tensions as low as 31 dyn/cm for more than 24 h without any apparent damage. The relevance of the surface tension regarding the fish toxicity of detergents in general is critically discussed.

Notes: Book reviewed in this article:SENSORY ECOLOGY: REVIEW AND PERSPECTIVES. Edited by M. A. Ali.BIOENERGETICS & GROWTH. FISH PHYSIOLOGY, Volume 8.786 pp. Edited by W. S. Hoar, D. J. Randall & J. R. Brett.THE PHYSIOLOGICAL ECOLOGY OF TUNAS. Edited by G. D. Sharp & A. E. Dizon.LAKE CHILWA: STUDIE OF CHANGE IN A TROPICAL ECOSYSTEM. Edited by M. Kalk, A. J. McLachlan and C. Howard-Williams.

Notes: A new histozoic species of myxosporidian, Myxosoma microspora n.sp., infecting the gill filaments of Mugil cephalus is described. Cysts measuring 0.5–1.0 mm in diameter were found attached to the gill filaments. Spherical or slightly oval, spores 4.8–5.2 μm in diameter, were present and possessed a thin outer mucous envelope which appeared as small conical protuberances at the ends of the equatorial axis. Polar capsules were pyriform in shape, equal in size and measured 1.6–2.0 × 1.0–1.2 μm; the polar filaments were 22–28 μm in length. There was a bean-shaped sporoplasm measuring 3.5 × 1.5 μm. No iodine vacuole was detected when the parasite was stained with Lugol's iodine.

Notes: Observations on haematological characteristics of albacore, Thunnus alalunga, and skipjack Katsuwonus pelamis, tunas, were made on blood samples collected from specimens immediately after they were caught and from an immobilized, restrained albacore sampled serially over a 24 h period. Results indicated eight types of blood cells in the peripheral circulation of both species. Lymphocytes were the most common leucocyte followed, in decreasing order, by neutrophils, eosinophils and monocytes in fish sampled immediately after being landed. Variations in differential and total white blood cell counts were observed in the immobilized, restrained albacore. High packed cell volumes and haemoglobin concentrations, typical for fast swimming fishes, were found in both species. Red blood cell counts were similar to those of other teleosts, and reticulocytes expressed as a percentage of mature erythrocytes were 6.1% and 5.2% for albacore and skipjack, respectively.

Notes: A stomach sampler for live fish is described and its construction outlined; 50 adult perch were sampled, subsequently killed and dissected to assess the efficiency of the device. Survival of previously sampled fish was followed using individually recognisable dorsal fin tags.

Notes: To determine the relation between swimming endurance time and burst swimming speed, elvers of the European eel, Anguilla anguilla (L.), were made to swim at speeds from 3.6 to 7.2 L (body lengths) s−1 in both fresh and sea water. Swimming endurance time of elvers averaging 7.2 cm total length decreased logarithmically with increased swimming speed from 3.0 min at 3.5 L s−1 to 0.7 min at 5.0 L s−1, and again logarithmically but with a lesser slope to 0.27 min at 7.5 L s−1. No differences were found between fresh and sea water elvers. In still water, elvers could swim at high speeds for about 10–45m before exhaustion, depending upon speed. Elvers would be able to make virtually no progress against water currents 〉50 cm s−1. Drift in coastal water currents and selective tidal transport probably involve swimming speeds below those tested in this study. Migration into freshwater streams undoubtedly involves avoidance of free stream speeds and a combination of burst and sustained swimming.

Notes: Unfertilised cod eggs showed a mean oxygen uptake rate at 5°C of 0.089 μl O2, dry wt.−1 h−1; this gradually rose to 0.768 μl O2 mg dry wt.−1 h−1 in eggs about to hatch. From hatching to complete yolk absorption larvae respired at 1.6 μl O2, mg dry wt.−1 h−1. During starvation following yolk absorption, uptake fell significantly to 1.1 μl O2, mg dry −1 h−1. Much of this decrease in oxygen consumption was shown to be caused by reduction in activity. Loss of weight during the embryo and larval phases could not easily be reconciled with total oxygen consumption; it is suggested that cod embryos and larvae may not rely solely upon endogenous energy reserves during development.

Notes: When plaice were injected intraperitoneally with either oyster glycogen or live Vibrio alginolyticus an acute cellular inflammatory response was observed. The duration of these responses, 7 and 15 days respectively, exceeded the time course of the mammalian cellular inflammatory reaction. Peak leucocyte numbers were found at 2–3 days and neutrophils, which were phagocytic, were more numerous than macrophages. Although the increase in macrophage numbers was less marked, these cells appeared more actively phagocytic than neutrophils. Cortisol injections and environmentally-induced stress caused a significant reduction in the extent of inflammatory cell infiltrates, while endotoxin significantly enhanced the response.