ALBERT

Description: The reproductive system is described from 15 giant squid Architeuthis sp., collected between 1972 and 2002 in South African waters. Distinctive features of the male reproductive system are the long muscular terminal organ, with elaboration of the anterior end, and modification of the tips of the ventral arms, probably hectocotilization. The spermatophoric organ has a long finishing gland that extends from the base of the gill. The terminal organ is differentiated internally into three distinct parts, involved in the guidance, storage, protection, expulsion and possibly the coating of spermatophores. Length of spermatophores in the terminal organ varied considerably. Several stages of spermatophores were found, from tentative to false to fully formed spermatophores, within a single animal. Distinctive features of the female reproductive system are a mesentery surrounding the main blood vessels of the ovary and attaching the ovary to the dorsal gladius chamber, multiple branching (at least three times) of the genital aorta that supplies the developing oocytes, high potential fecundity (3.5–6.2 ± 106 oocytes), small eggs and short oviducts that suggest intermittent (extended) spawning. Large concentrations and single spermatangia were found in various places in females, indicating non-specific deposition. The transfer of spermatophores is probably rapid, perhaps because of considerable sexual size dimorphism (at maturity, males are much smaller than females). Implants in males are probably self-induced since the majority were found within reach of the terminal organ opening (primarily on the ventral arms in males).

Description: The vertical distribution patterns of paralarvae from several abundant cephalopod taxa were examined from depth-stratified tows in the northeast Pacific (44–56°N, 145–165°W) during three summer surveys in 1999–2001. A total of 309 cephalopods representing 10 taxa in three families were collected. Gonatid squids composed 97% of the total catch, and the most numerous taxa were Berryteuthis anonychus (59% of the total catch), Gonatus spp. (21%) and Gonatopsis borealis (17%). B. anonychus and Gonatus spp. were both most abundant in the upper 20 m; catches of both taxa varied significantly with depth and were significantly higher above the thermocline than in and below the thermocline. Gonatopsis borealis was collected mostly between 20 and 50 m, and catches were significantly higher in the thermocline than above and below the thermocline. Paralarvae of the three major taxa showed no evidence of diel vertical migration. Mantle lengths of Gonatus spp. and G. borealis each varied significantly with depth, and Gonatus spp. showed a strong positive correlation between mantle length and depth.

Description: A new species of eledonid octopus is described from the southwestern Atlantic Ocean from depths between 90 and 1000 m off the coasts of southern Brazil, Uruguay, and Argentina. This species, Graneledone yamana is characterized by having a papillose skin, two well developed 'horns' above the eyes, small gills with 5-7 lamellae on the outer demibranch, arms with uniserial suckers, 35-80 on females and 26-70 on males. The third right arm is hectocotylized, the ligula is small, the calamus is large and well differentiated. Ink sac absent. These characters differ from all other known Graneledone species from the southern oceans.

Description: Phylogenetic analysis conducted on a 784-bp fragment of 82 actin gene sequences of 44 coleoid cephalopod taxa, along with results obtained from genomic Southern blot analysis, confirmed the presence of at least three distinct actin loci in coleoids. Actin isoforms were characteri zed through phylogenetic analysis of representative cephalopod sequences from each of the three isoforms, along with translated actin cDNA sequences from a diverse array of metazoan taxa downloaded from GenBank. One of the three isoforms found in cephalopods was closely related to actin sequences expressed in the muscular tissues of other molluscs. A second isoform was most similar to cytoplasmic-specific actin amino acid sequences. The muscle type actins of molluscs were found to be distinct from those of arthropods, suggesting at least two independent derivations of muscle actins in the protostome lineage, although statistical support for this conclusion was lacking. Parsimony and maximum-likelihood analyses of two of the isoforms from which 〉30 orthologous coleoid sequences had been obtained (one of the cytoplasmic actins and the muscle actin) supported the monophyly of several higher-level coleoid taxa. These included the superorders Octopodiformes and Decapodiformes, the order Octopoda, the octopod suborder Incirrata, and the teuthoid suborder Myopsida. The monophyly of several taxonomic groups within the Decapodiformes was not supported, including the orders Teuthoidea and Sepioidea and the teuthoid suborder Oegopsida. Parametric bootstrap analysis conducted on the simulated cytoplasmic actin data set provided statistical support to reject the monophyly of the Sepioidea. Although parametric bootstrap analysis of the muscle actin isoform did not reject sepioid monophyly at the 5% level, the results (rejection at P = 0.068) were certainly suggestive of sepioid nonmonophyly.

Description: A type of apparent photoreceptor, the nuchal organ, is described in the sepiolid squid Euprymna scolopes. These vesicles are identified in a variety of other cephalopod species. The nuchal organs have specific structural similarities to the already well-described photosensitive vesicles. Both organs have a distinct vesiculate structure and possess a rind consisting of several types of cells. Certain rind cells from both organs send processes with microvilli into the lumen of the vesicle forming a core area. Within the cores of both organs numerous microvilli occupy much of the core volume. These histological similarities provide strong evidence that the nuchal organs, like the photosensitive vesicles, are photoreceptors. Three distinct differences also exist between the nuchal organs and photosensitive vesicles: (1) the location of the nuchal organs differs from that of all known photosensitive vesicles in cephalopods; (2) the location of the nuchal organs is highly conservative in decapod cephalopods compared to the varying locations of the photosensitive vesicles; (3) the degree of structural order generally found within photosensitive vesicles is not apparent in the nuchal organs. The function of the nuchal organ is probably different from previously described photoreceptors in cephalopods.

Description: A mature female Galiteuthis glacialis (430 mm mantle length) was caught south of the Falkland Islands (53°S, 58°W) at a depth of 976-1001 m over a bottom depth of 1582-2378 m. A total of 8 spermatangia (15-19 mm in length) were found inserted into the mantle wall, which was of gelatinous consistency. Its ovary contained 3 605±42 oocytes, mostly 2.2-2.5 mm in length, and there were 21 ripe eggs (3.0-3.2±2.2-2.7 mm) in the oviducts. Only one resorpting oocyte (1.4 mm) was found. This is the only description of a mature female of this species, though two spent females have been previously described and three more mentioned by other authors.

Description: The Patagonian longfin squid Loligo gahi undertakes horizontal ontogenetic migrations on the Falkland shelf: juveniles move from spawning grounds located in shallow, inshore waters (20–50 m depths) to feeding grounds near the shelf edge (200–350 m depths). Immature squid feed and grow in these offshore feeding grounds and, upon maturation, migrate back to inshore waters to spawn. The possible influence of environmental factors on L. gahi migrations was investigated using data from oceanographic transects, crossing the region of known L. gahi occurrence. They were made from the inshore waters of East Falkland eastwards to depths of 1250 m on a monthly basis from 1999 to 2001. Four main water types were found in the region: Shelf, Sub-Antarctic Superficial and Antarctic Intermediate water masses, and Transient Zone waters. The inshore spawning grounds occur in the Shelf Water mass, whereas the feeding squid (medium-sized immature and maturing individuals) were associated with the Transient Zone. The 5.5°C isotherm appeared to mark the limit of squid distribution into deeper waters in all seasons. Seasonal changes in water mass characteristics and location were found to be important for seasonal changes in L. gahi migrations on the Falkland shelf.