ALBERT

Description: A detailed analysis of lower rostral beak length (LRL) to body size and wet body mass measurements was carried out for the squids Loligo forbesi, Todarodes sagittatus and Todaropsis eblanae. Specimens were sampled in the northern North Sea during two research cruises of FRV WALTHER HERWIG III in January/February of 1998 and 1999. Altogether 241 specimens of Loligo forbesi (ML = 45–376 mm), 108 specimens of Todarodes sagittatus (ML = 173–325 mm) and 97 specimens of Todaropsis eblanae (ML = 30–127 mm) were investigated to correlate lower rostral beak length with both mantle length and wet body mass. Linear relationships between LRL and mantle length and powerfunctional relationships between LRL and wet body mass were calculated for all three species. By calculating these correlations separately for males and females, no obvious sex-specific relationships were found. The presented data will upgrade the information on beak/mantle length/body mass relationships of major cephalopod species of the North Sea. They provide essential information for future use in estimates of cephalopod prey biomass in North East Atlantic top predators such as whales, seals, seabirds and fishes.

Description: Biochemical genetic variation in the highly abundant squid species from the North Pacific Ocean was examined in relation to their intraspecific differentiation and population structure. A large amount of data collected over a period of approximately 15 yrs was analyzed using protein electrophoresis as a basic research tool. In total, approximately 750 individuals of Ommastrephes bartramii (LeSueur, 1821), 300 individuals of Todarodes pacificus Steenstrup, 1880, and 5800 individuals of Berryteuthis magister (Berry, 1913) were covered by the approach. A geographic pattern of population genetic variability was observed in O. bartramii, with major genetic differentiation attributable to inconsistency in allele frequency distribution and in levels of genetic variation between the squid from the western and eastern parts of the species broad range in the North Pacific Ocean. In T. pacificus from the Japan Sea, significant intraspecific genetic differentiation was largely due to allele frequency variability between two groups of seasonal cohorts: autumn group, consisting of the autumn-spawning squid, and non-autumn group, comprised of the winter-, spring- and summer-spawning squid. An apparent pattern of genetic differentiation was observed in B. magister, which could be related to intersubspecific differences between the squid from the Japan Sea, and northwest Pacific Ocean region, including the Kuril and Commander islands, and Okhotsk and Bering seas. Much less pronounced though significant population genetic variability was revealed between conspecific aggregations of the squid within the northwest Pacific Ocean, where they differ from each other according to geographic proximity, and the most clear differentiation appeared between the Okhotsk-Kuril and Bering groups of the squid.

Description: Cephalopods (n = 515) were identified from a series of plankton and fine meshed mid-water trawls, taken between 1977 and 1999, around the British Isles. The collections were not directed at cephalopods, but provide valuable information on the distribution of planktonic species and on the paralarvae of the benthic species. The most abundant species in neritic areas were the octopod Eledone cirrhosa and the sepiolids, Sepietta oweniana and Sepiola atlantica. Eledone cirrhosa were common in samples to the north and west of Scotland, particularly in early summer. The mantle lengths of E. cirrhosa were 4–8 mm, indicating a brief planktonic existence or, perhaps, net avoidance by larger specimens. In the shelf-break collections from the west of Scotland and Ireland the squids Brachioteuthis spp., Gonatus sp., Teuthowenia megalops and rynchoteuthions of the Ommastrephidae were abundant. Two types of rhynchoteuthion were found and were probably Todarodes sagittatus, Illex coindetii or Todaropsis eblanae. Despite the abundance of Loligo forbesi around the British Isles, it was rarely taken in plankton collections, probably indicating that it does not have a planktonic paralarva.