ALBERT

Description: Food samples from 27 Buller’s mollymawks Diomedea bulleri from the New Zealand region showed that cephalopods were, by frequency of occurrence and by mass, their preferred food. Fish, crustaceans, and tunicates, in decreasing order of importance, also were taken. Seventeen species of Cephalopoda were identified by their beaks, with 78.5% of individuals belonging to the Ommastrephidae (77% Nototodarus spp.) and 10% to the Histioteuthidae. The diet was compared with that of four other small species of Diomedea, and found to be similar to that of D. chrysostoma, D. irrorata, and D. cauta, but different from that of D. melanophris, whose preferred food is euphausiids. Squid-fishing operations around New Zealand may come into competition with Buller’s mollymawk.

Description: Stomach contents of 68 black petrels, Procellaria parkinsoni, 12 Westland black petrels, P. westlandica, and 3 white‐chinned petrels, P. aequinoctialis, were compared. The main prey were Cephalopoda and fish, and these indicated predominantly nocturnal feeding with selection for bioluminescent forms. There is marked latitudinal variation in the Cephalopoda available to these petrels.

Description: A link is proposed between the processes that led to the evolution of large species of squid and the highly variable, cyclic recruitment seen in squid fisheries. Maximum growth requires maximal feeding and minimal routine metabolism at optimum temperatures, which decrease as squid grow. Topographically induced upwelling zones, inshore of western boundary currents, provide productive environments with appropriate temperatures for all life stages. Most squid are small and live in the tropics or subtropics; locomotor constraints prevent them from swimming long distances. Long annual migrations to spawn upstream in current systems require short-lived squids to maximize rates of growth. Therefore, such systems provide the opportunity and a powerful selective advantage for large size and rapid growth. Increased fecundity and cannibalism provide additional directional selection for large individuals. Current systems show food production peaks (blooms); paralarval release must match these to increase survival. Because squid are semelparous, disruption of delicately balanced lifecycles by physical events can virtually annihilate stocks. Recovery probably requires that populations of large squid "re-evolve" from smaller, more-stable tropical populations of small squid. This recovery phase may extend the "down-side" of abundance cycles. Studies of squid/current systems have focused on western boundary currents, but the Illex complex also associates with eastern boundaries. Such populations are generally smaller than in larger systems, supporting the hypothesis, but more detailed comparisons are required.

Description: During a cruise in March 1988 dedicated to investigation of the marine resources of South Africa's continental slope, 62 species in 22 families of Cephalopoda were collected from the Cape Canyon and Cape Point Valley. Multivariate analysis revealed a clear distinction between cephalopods of the upper and lower continental slope in both benthic and epibenthic habitats. Todaropsis eblanae and Todarodes angolensis were indicator species for the upper slope benthic, from 300 to 500 m, but on the lower slope, in 700–900 m of water, they were replaced by Histioteuthis miranda and Opisthoteuthis agassizii. In the epibenthic, both upper and lower slopes were dominated by Abraliopsis gilchristi and Lycoteuthis ?diadema, but other species characteristic of the lower slope were the oceanic species Mastigoteuthis hjorti, Ctenopteryx sicula and Taonius sp. A. Cranchia scabra indicated the presence of oceanic water at stations 700–900 m deep. Other species of significance in the catches were Todarodes filippovae, Histioteuthis macrohista, Rossia enigmatica and Bathypolypus valdiviae. Species affinities indicate that the cephalopod fauna of the southern African continental slope includes the following zoogeographic components: southern African endemic, circum-Subantarctic species associated with Antarctic Intermediate Water, circum-global southern tropical/subtropical, tropical Indo-Pacific and cosmopolitan tropical/subtropical.

Description: Literature on trophic relationships in the Benguela ecosystem has stressed the importance of cephalopods as prey of groundfish. The groundfish community of the shelf and upper slope of southern Africa is dominated by the Cape hakes, and the results presented (1984–1991) confirm that both species of hake are important predators of cephalopods, especially taking into consideration the abundance of hake in the ecosystem. However, geographic, seasonal and species variability are evident in the patterns observed. The main prey species are Sepia spp. (predominantly Sepia australis), Loligo vulgaris reynaudii, Todaropsis eblanae and Lycoteuthis ?diadema. The last-named is an important food organism for fish. Its systematic status needs revision, however. Qualitative results of studies of cephalopod predation are also provided for kingklip and monkfish.

Description: Cephalopods of importance in the Benguela ecosystem include Loligo vulgaris reynaudii, Todarodes angolensis, Todaropsis eblanae, Lycoteuthis ?diadema, Sepia australis, Octopus spp. (up to three species) and Argonauta spp., and possibly also Ocythoe tuberculata and Rossia enigmatica. Species which may prove important as a result of further research are Lolliguncula mercatoris, Ommastrephes bartramii, Todarodes filippovae, Histioteuthis miranda and Abraliopsis gilchristi. "Importance" is defined on the basis of "survey abundance" (including commercial fisheries) and their trophic links with other organisms. Use of the latter criterion indicates that Sepia australis, Todaropsis eblanae and Lycoteuthis ?diadema are sufficiently abundant to be exploited by fisheries. Unknown factors are dispersal, availability and market considerations. The only examples of cephalopods feeding on commercial species of fish are Loligo v. reynaudii feeding on anchovy Engraulis capensis and Cape hakes Merluccius capensis and/or M. paradoxus in the southern Benguela and Todarodes angolensis preying on Cape hake in the northern Benguela. Such feeding is opportunistic and is not believed to threaten the fish stocks. Predators of cephalopods are mostly opportunistic, switching to other prey when cephalopods are not available. There is no evidence that such predators pose a threat to the Loligo fisheries. The opportunistic nature of cephalopods as prey and predators makes quantification of predation (in both directions) difficult. Data for such quantification are, as yet, unavailable.

Description: The present study contributes new information on the cephalopods off Namibia, contains the first record of Ornithoteuthis volatilis (Sasaki, 1915) in the Atlantic, and adds records of six species in the Benguela Current and three species in Namibian waters. The presence of certain species seldom encountered in the Benguela Current has been confirmed. A compilation of the cephalopod fauna off Namibia had also been included, listing 65 species. Additional morphological data on Stoloteuthis leucoptera, Lycoteuthis lorigera, Architeuthis sp., Pholidoteuthis boschmai, Ornithoteuthis volatilis, Eledone nigra, and Graneledone sp. have been provided. The status of the genus Lycoteuthis has been reviewed in the light of the first collection of Lycoteuthis lorigera (Steenstrup, 1875) males in the Atlantic, and Lycoteuthis diadema (Chun, 1900) has been considered to be a synonym for Lycoteuthis lorigera

Description: The results of ichthyoplankton surveys carried out by the Instituto Nacional de Pesca (INAPE) in the Argentine–Uruguayan Common Fishing Zone (AUCFZ) in summer 1980 and the winters of 1980–1982 are presented. In addition, the results of joint research with INIDEP, the Argentine and Japan Fisheries Agency, on larvae, juveniles and adults of the short-finned squid Illex argentinus carried out in winter 1989 are given, as are data obtained during the joint sardine and anchovy recruitment project carried out by R.V. Meteor in November/December 1989. The short-finned squid Illex argentinus is the most important cephalopod resource of the area, and an extended fishery is carried out on the Patagonian shelf and in the proximity of the Falkland Islands. The fishing season in the AUCFZ, for pre-spawning and spawning animals, extends from early autumn to winter (March–August). Abundance of rhynchoteuthion larvae (417–485 larvae·10 m−2) was greatest in winter in surface temperatures of 12,1–16,9°C and surface salinities of 34,8 – 35,2 × 10−3. The distribution of the larvae is related to the western boundary of the Brazil Current and the convergence front.

Description: The question whether the chokka squid Loligo vulgaris reynaudii resource can be managed effectively is examined in the light of developments in the fishery and knowledge of the resource gathered in recent years. The history of the fishery since its inception in 1985, management controls and the current state of knowledge of stock identity, distribution, seasonality and abundance, life cycle and population dynamics are reviewed as a background to a discussion of management alternatives. Long-term measures, such as fleet limitation, seasonal closures and de facto closed areas and size limits, all appropriate in the early stages of a fishery when knowledge is limited, should be replaced by more-flexible alternatives as knowledge improves. Methods of stock assessment, stock-recruitment studies and further basic biological analyses are recognized as being crucial to improving management methods. An explanation embracing physical oceanographic features and plankton productivity in the vicinity of the spawning grounds is advanced for the mechanisms underlying hatchling survival. The possible contribution of trophic studies to squid management is recognized. Effective management of the chokka squid resource is concluded to be possible provided that the specific areas needing attention be addressed by means of goal-orientated research. Rational, but not necessarily optimal, management decisions can, however, be made even in the absence of stock-recruitment data, by the employment of common-sense measures which generally include some form of effort control.

Description: The production of shiga toxin (Stx) is a critical step in the establishment and progress of enterohemorrhagic Escherichia coli (EHEC) infections. The possible release of Stx from dead and dying bacteria, and the risk of resistance development have restricted the usage of antibiotics against EHEC. The chlorinated quaternary ammonium compound, strepthonium A, was isolated from the culture of Streptomyces sp. SBT345 that was cultivated from the Mediterranean sponge Agelas oroides. The structure was elucidated and confirmed by spectroscopic analyses including 1D and 2D NMR, ESI-HRMS, as well as ESI-HRMS2. Strepthonium A follows Lipinski's rule of five with respect to its molecular weight, CLogP values and the number of hydrogen acceptors and donors. Verotoxin ELISA assay demonstrated that Strepthonium A reduced the Stx production in EHEC strain EDL933 at 80 μM concentration without growth inhibition. This study demonstrates the potential of strepthonium A in restraining the production of Stx in EHEC infections.