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: Early life cephalopod stages were collected around tropical seamounts and oceanic islands off the north-eastern coast of Brazil. A total of 511 specimens was caught with oblique Bongo net hauls between 150 m depth and the surface during a joint Brazilian/German oceanographic expedition with the RV VICTOR HENSEN in January/February 1995. Mean density of cephalopods was low with 24 ind 1000 m−3. Fifteen families representing at least 21 genera, from which 11 species were identified. The findings revealed a typical tropical and oceanic cephalopod assemblage. The most abundant families were Enoploteuthidae (27.6%), Ommastrephidae (20.9%), Onychoteuthidae (11.2%), Cranchiidae (10.4%) and Octopodidae (9.2%). Less abundant families were Octopoteuthidae, Thysanoteuthidae, Cthenopterygidae, Lycoteuthidae, Mastigoteuthidae, Tremoctopodidae, Argonautidae, Chiroteuthidae and Bolitaenidae. Highest cephalopod densities occurred along the Fernando de Noronha Chain (34 ind 1000 m−3). Small-sized Enoploteuthidae and Onychoteuthidae dominated in that region. Around the North Brazilian Chain overall cephalopod density was 31 ind 1000 m−3 where again, Enoploteuthidae were most abundant, closely followed by Ommastrephidae. Cephalopod abundance was the lowest (13 ind 1000 m−3) around the St. Peter and St. Paul Archipelago. However, cephalopod diversity was highest in this region (17 genera) with Enoploteuthidae dominating, followed by Cranchiidae. Cephalopod mantle lengths (ML) ranged from 0.8 mm to 25 mm. The majority of specimens were small-sized with 65% below 3 mm ML, and 81% below 4 mm ML. All major genera and species are illustrated and their meso-scale distribution patterns are discussed. The results provide new information on the species composition and distribution patterns of early life cephalopods in tropical seas.

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.