Description: Records of 158 observations of cephalopods from submersibles, primarily the Johnson Sea-Link, have been compiled through collaboration with several investigators. These observations include 118 videotape sequences, 58 collected specimens, and numerous shipboard photographs of live animals. At least 33 species have been observed to date; a few species have been observed repeatedly and could be good subjects for directed studies. The methods developed for in situ observation and subsequent collection of specimens with little or no damage allow descriptions of behavior, morphology, physiology, and distribution that are not possible with other methods of collecting.

Description: Specimens and data suggest that larval short-finned squid, Illex illecebrosus, may concentrate in water where density is approximately 26.7, indicating that spawning occurs in the subsurface interface where Slope Water mixes with the Gulf Stream. Because these water masses occur year-round within the range of I. illecebrosus, spawning may be a prolonged or progressive process along the shareward edge of the Gulf Stream. The distribution of other species indicates mesoscale spatial separation of young cephalopods in the vicinity of the Gulf Stream.

Description: Two cruises in the western North Atlantic collected 38 trawl samples between the Bahamas and New England. Ofthe 22 cirrate octopods taken in these samples, 17 came from the area north of the Bahamas. Pooled catch rate (specimens per hour of bottom trawling time) was significantly higher north of the Bahamas than in any other area sampled. Although the taxonomy of these gelatinous benthopelagic cephalopods is not yet settled, morphological characters from these specimens indicate that this aggregation includes at least four species. Only one species (Cirrothauma murrayi) was widely distributed in these samples.

Description: The larval development of lllex is described and figured with particular attention to development of the tentacles and the fourth pair of arms. The larvae can be identified by the presence of relatively short fused tentacles which have 8 suckers of uniform size. By the time the tentacles separate they have developed 8 rows of sucker buds in the dactylus. Growth of the tentacles appears to occur at the base as well as the distal tip and the fused area separates rapidly at about 8.50 mm dorsal mantle length. Larval lllex collected primarily in subsurface samples from boreal waters along the outer Continental Shelf of the Middle Atlantic Bight in February and March 1977 are considered to be I. illecebrosus. lllex sp. larvae were also taken in subsurface samples from tropical waters in the mid-shelf region of the Middle Atlantic Bight during August 1977 and in surface samples over the Hatteras Abyssal Plain in February and March 1978.

Description: The gills of cirrate octopods are known to be unusual with terms 'half orange' and 'sepioid' commonly used to describe them. The structure and relationships of these gills to other cephalopod gills have not been adequately investigated. In this paper we investigate the evolution of the gills of cirrates and of octopodiforms in general. Octopodiform gills differ from the primitive cephalopod gill, as exemplified by the gills of Nautilus and decapodiforms, by the presence of septa along the axes of the primary and secondary lamellae. The septa apparently constrain the respiratory surfaces to form tree-like folds rather than the fan-like folds of other cephalopods. In members of the Vampyromorpha, the sister taxon of the Octopoda, gills have a peculiar circulation pattern that seems to be a unique adaptation to its deep-sea habitat. The arrangement of blood vessels in the cirrates involves the repositioning of the primary efferent vessels deep within the gill. In addition, an axial anastomosis of superficial afferent vessels resulted in an appearance similar to a decapodiform gill but with afferent rather than efferent vessels on the 'top' of the gill. This, combined with the lack of a branchial canal and the presence of bilaterally symmetrical lamellae, has resulted in the appearance of a 'sepioid' gill. The 'half-orange' gill appears to result from a foreshortening and rotation of the gill to give the impression of a nearly radial arrangement of equal-sized primary lamellae rather than the typical serial arrangement of primary lamellae that decrease in size distally. Apparently, the adaptations of the octopodiform gill resulted from a need to increase the efficiency of oxygen uptake. We suggest that a major factor in the evolution of the Octopodiformes was the adaptation to a habitat low in oxygen.

Description: Starvation resulting from failure to feed successfully after absorption of the yolk reserves has been proposed to be a major source of pre-recruitment mortality in squids. To test this hypothesis, methods must be developed to determine whether paralarvae have fed successfully at sea. When paralarvae are stained with Alcian Blue and then cleared with trypsin, the entire digestive tract can be examined intact for the presence of food. This method was used for Abralia trigonura and Sthenoteuthis oualaniensis paralarvae from Hawaiian waters. Approximately 9% of the former and 16% of the latter contained recognizable food material, mostly crustacean fragments. Food was found in the stomach, caecum, and intestine. The smallest specimen of A. trigonura with recognizable food in its digestive tract was 2.2 mm dorsal mantle length (DML), while for S. oualaniensis the smallest was 5.2 mm DML. The method is also useful for visualizing the ontogeny of the digestive-tract organs, beaks and radula, and other organs such as statocysts and eyes.