Akkar (Todarodes sagittatus (Lamarck)). Norske undesøkelser i april-desember 1980. | The squid (Todarodes sagittatus (Lamarck)). Norwegian investigations, April-Desember 1980

During the second half of 1980 T. sagittatus invaded the northeasternNorwegian Sea and adjacent coastal areas in great abundance.The invasion coincided with the occurrence of large quantitiesof salps. Squid still remained in coastal waters in January1981.Materials for investigation were obtained from research cruises innortheast Atlantic waters in April - May, in the North Sea in July,and in the Norwegian Sea and coastal waters of Norway in August -December .Length and weight.The mean dorsal mantle length (DML) of squid hatched during theautumn of 1979 increased from 16-18 cm in April to 31-32 cm (males)and 35-38 cm (females) in December. A specimen of DML 59 cm andweight (W) of 5300 g was reported caught in October.The relation between weight and mantle length W = a(DML)b wascalculated on material from 1979 - 1980.Males (DML 17-41 cm) : a = 0.0181, b = 3.0181, r2 = 0.9447.Females (DML 14.5-50 cm): a = 0.0180, b = 3.0170, r2 = 0.9419.Liver weight.On the Porcupine Bank and at st. M in the Norwegian Sea the liveraveragely constituted about 7% of the total weight, in other areas9-10%, with individual variations of 3.7 - 17.2%.Sex proportions.In fjords and coastal areas males constituted 0-10%, on the banksabout 13%, in oceanic areas 22-28%. The low proportion of males inthe fjords is ascribed to cannibalism.Maturation.In April - May, males with DML above 30 cm were maturing, most ofthem with spermatophores developed. In October - November a fewlarge males had developing testes.During July - December all females taken were immature. In April -May about 50% of females with DML above 35 cm were maturing ormature, with nidamental glands 50-100 mm in length. One female withDML 44 cm had eggs (oocytes) in maturity stage 3. Total number inthe ovisac was calculated to 84 500, considerably above earlierliterature records.Stomach contents.As recorded earlier, fish were most common. Blue whiting, pearlside,Notoscopelus krøyeri, Notolepis rissoi krøyeri, redfish,herring or sprat and whiting were identified. Of squid, T. sagittatus,Gonatus fabricii and small octopods were found. Of other organismskrill and Hyperiids were most common. Pasiphaea sp., Pareuchaetasp., Nereis sp., Eukrohnia sp. were also identified.Age.A report on daily rings in the statoliths has been published. Theage readings revealed two main periods of hatching, September -November and April - June, but reproduction also occurs at othertimes of the year. Squid caught in October, are probably one yearor less of age, but the specimen with DML 59 cm might be 11/2 - 2years old.Fishery.In 1980 the fishery yielded 2 500 m. tons. The possible yield wasestimated to 25-50 000 tons.