New data on the life history and ecology of the deep-sea hooked squid Taningia danae

Abstract

Three specimens of Taningia danae were captured in the northern Spanish (eastern Atlantic) waters in late 2000. The total weights of the animals, two females and one male, were 66, 124 and 19 kg, respectively. Both females were maturing with no trace of eggs in the oviduct. The potential fecundity of the largest female was close to 5 million oval-shaped oocytes ranging from 0.4 to 1 mm. This female represented the heaviest record of T. danae to date. A description of the first mature male of this species is also undertaken. The reproductive strategy adopted by this species seems to rely on multiple spawning. The most remarkable feature of the male was the presence of a long penis with a total length of 73 cm that protruded 23 cm beyond the mantle. The number of growth increments in the statoliths was 647 and 1052, for each female, respectively. Assuming that these growth increments are deposited daily, the estimated age of these specimens would be 21 and 33 months, respectively. Remains of the blue whiting Micromesistius poutassou, some exoskeleton fragments of crustaceans and small hooks of Gonatus sp. were present in their stomach contents. The geographical and vertical distribution and the possible influence of water temperature and upwelling events on the growth of this species are discussed.