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We describe size at age, growth, and population structure of short-finned squid (Illex illecebrosus) from Newfoundland waters during 1990. Ages were estimated from statolith increment counts and used to back-calculate hatching dates. Hatching ranged between December and June with the hatching months of March to May predominating. Constant interchange of individuals in the inshore population was evident in that the modal month of hatching progressed from March within the earliest (July) sample to May within the latest (November) sample. Within the mantle length range available, growth was adequately expressed by a linear model. Females grew faster than males, and during the March to May months of hatching, length at age and growth rate increased with hatching month. This positive effect of late time of hatching was also seen in growth in mass and in gonad development and sexual maturation.

SUMMARY: Two ongrowing experiments were conducted using a raft deployed for rearing mussels during summer and winter in the Ria of Vigo, Galicia, NW Spain. Two 3 m x 1.5 m x 6 m galvanized iron ongrowing cages were suspended from this platform, each equipped with dens constructed from PVC pipe. Small common octopus (Octopus vulgaris) were captured by the small-scale creel fishery in the ria and placed in one of two sex-specific experimental cages. Specimens were fed a standard diet (fish, decapod crustacean and mussels) at a daily feeding rate of 5% of the total weight of the animals in each cage. Due to the very high mortality as a result of decreased salinity in the winter experiment and spawning during the summer experiment, only data from the first 75 days of each experiment were compared. Growth rates were significantly higher in summer than in winter for both sexes, which was probably due to higher ambient culture temperatures during summer. Mortality was also higher during summer than winter. It was concluded that culture of common octopus on mussel rafts may be viable, especially if problems related to salinity, the acquisition of specimens from the wild and losses due to spawning can be reduced.Keywords: Octopus vulgaris, growth, ongrowing, NW Spain. RESUMEN: CRECIMIENTO DE PULPO COMÚN (OCTOPUS VULGARIS) EN JAULAS FLOTANTES. -En este estudio se realizaron dos experimentos de engorde de pulpo común (Octopus vulgaris) en jaulas suspendidas desde una plataforma de cultivo de mejillón en la Ría de Vigo (Galicia, noroeste de España). Las dimensiones de cada jaula de hierro galvanizado fueron 3 x 1,5 x 6 m, y cada una de ellas estaba equipada con cobijos de PVC. Los pulpos de pequeño tamaño se obtuvieron en la pesquería de la Ría de Vigo y se introdujeron por separado, machos y hembras, en cada una de ellas. Los ejemplares fueron alimentados con una tasa de alimento del 5% del peso medio de los animales de cada jaula con una dieta estándar compuesta por peces, crustáceos decá-podos y mejillón. Únicamente se utilizaron los datos de los 75 primeros días de cada experimento debido a la elevada mortalidad de los animales al final del experimento de inverno por descenso brusco de la salinidad y al desove de los animales de verano. Las tasas de crecimiento de ambos sexos fueron significativamente más altas en verano que en invierno posiblemente debido a las mayores temperaturas ambientales durante el estío. La mortalidad fue más elevada en verano que en invierno. Esta experiencia indicó que el engorde de pulpo en jaulas sería viable, especialmente si los problemas debidos al descenso de la salinidad, la obtención de ejemplares de la naturaleza y al desove de las hembras pueden reducirse.

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A sample of about 1000 snow crabs (Chionoecetes opilio) from NAFO (Northwest Atlantic Fisheries Organization) Division 3K (Northeast Newfoundland Shelf), taken by bottom trawl for studies of their stomach contents, indicated that about 12 benthic or demersal prey types occurred in their diet from that area. The most frequently occurring prey types were sabellid polychaetes, crustaceans (shrimp, crabs and smaller crustaceans) and infaunal clams (Macoma calcarea). Shrimps (especially pink shrimp, Pandalus borealis) and fishes (especially capelin, Mallotus villosus) were the most important prey types with respect to their percentage contribution to the total food mass. Brittle stars (Ophiuroidea) were regularly preyed upon by males but were virtually absent from the stomach contents of mature females. Males preyed more heavily upon fish and infaunal prey types (polychaetes and clams) whereas females preyed more heavily on shrimp and readily-accessible epibenthic prey types (gastropods, crabs and sea urchins). Males appeared to be more capable predators than were mature females. Predation on fish was related to predator size for both sexes but was most commonly practiced by males that were larger than the maximum size of mature females. However predation on fish was also more commonly practiced by males than by mature females at comparable sizes. There were no other effects of predator size in the predation by males whereas predation by mature females on clams, shrimp, gastropods, sea urchins, and possibly polychaetes increased with predator size. Cannibalism was most frequently practiced by intermediate-sized crabs and more frequently by females than males. Cannibalism was more common in our study than in others reported to date and may represent an important densitydependent source of mortality that could affect recruitment levels and patterns.

A technique has been developed which simplifies the ageing of short-finned squid (II'ex illecebrosus) through microstructural examination of the statotiths. The spatial pattern of growth increments was studied with the use of light and scanning electron microscopy. Daily growth increments in statoliths were validated by employing chemical "time" markers (strontium and tetracycline) and laboratory-reared animals of known age. Increment formation continued through periods of food deprivation and minimal temperature fluctuations.

The current public perception is that there is little reason for concern for the conservation of marine invertebrates, in part due to the scarcity of emblematic species to represent that diverse group. This paper shows that giant squid can be considered an emblematic species to represent concern for the conservation of marine invertebrate biodiversity because it satisfies all the requirements of an emblematic species. It shows that Architeuthis attracts public interest and attention and can serve as an indicator of oceanographic conditions and ocean climate change. It asserts that Architeuthis can represent concerns for vulnerable marine ecosystems associated with submarine canyons and that it belongs to a broad diverse phylogenetic group of organisms associated with these canyons, sharing common concerns with that group with respect to vulnerability and conservation. This study also advocates that the giant squid can serve as an indicator of effects of ecosystem stress resulting from anthropogenic effects including ocean acidification and warming. It is also shown to be vulnerable to such anthropogenic effects as fishing, acoustic seismic exploration and, possibly, pollutants.