Reproductive Biology and Scale of Maturity Stage of Reproductive Systemof Female Squid (Illex illecebrosus)

Oogenesis and the development of the reproductive organs in Illex illecebrosus females was studied. The sample analyses were obtained from the area between Cape Hatteras and the Grand Bank in 1966-1983. To investigate the oogenesis, 10 gonads were taken from the females with the mantle length of 15-30 cm at allmaturity stages (except spawning). Approximately 2,000 specimens were studied to obtain knowledge of thedevelopment of the reproductive system organs during the ontogenesis. More than 50,000 females were sampled to analyse the maturation dynamics and the distribution during their life cycle. Data on the spawning andspent females were obtained for Illex argentinus

Growth, reproduction and feeding of the tropical squid Ornithoteuthis antillarum (Cephalopoda, Ommastrephidae) from the central-east Atlantic

Length composition, age, growth, reproductive biology, feeding and parasites were studied using 432 individuals of the squid Ornithoteuthis antillarum (1.8-138 mm ML) collected in the open waters of the tropical central-east Atlantic. In the region studied, only a small-sized and early-maturing population of O. antillarum occur. Statolith shape, development and microstructure have several peculiar features setting O. antillarum apart of other ommastrephids. Assuming growth increments within statoliths to be daily, maximum age of squids does not exceed 182 days. Growth rates of juveniles and immature squids are high and similar to another fast-growing ommastrephid Sthenoteuthis pteropus, but they decrease considerably with the onset of maturation. Potential fecundity varies from 50,000 to 220,000 oocytes. It is suggested that the squid is a multiple spawner with frequent releases of small-sized (No disponibl

Ecological-Fishery Forecasting of Squid Stock Dynamics under Climate Variability and Change: Review, Challenges, and Recommendations

24 pages, 3 figures, 5 tablesGlobally, cephalopods support large industrial-scale fisheries and small-scale to partly large-scale local artisanal fisheries. They are of increasing economic importance as evidenced by the rapid rise in their global landings from 1950 to 2014. Cephalopods are sensitive to environmental variability and climate change and many if not all species show wide fluctuations in abundance. This is most evident in ommastrephid nerito-oceanic squid since their life cycle is associated with boundary currents that are changing with climate change. The inter-annual variability in catch presents challenges for fishers and managers due to the ‘boom-or-bust’ nature of the fishery. A key barrier to rational management of squid fisheries is the low level of development of fishery forecasting. Despite substantial progress made in relating squid population dynamics to environmental variability and change, several challenges remain to develop forecast products to support squid fisheries management. Ideally, squid fisheries management needs a forecasting system that includes all time-scales of forecasting, and especially short - and medium-terms forecasts. The present overview first provides current knowledge of the effects of climate change and variability on squid population dynamics, challenges and opportunities to advance ecological-fishery forecast products, and finally a roadmap is proposed for future development of forecasts products to support squid sustainable fisheries management. As for the adoption of specific forecasting methods to the squid fishery management process, what is important is the relationship between needs, feasibility, and the ultimate success of a forecast will be determined by whether it is used by end-usersPeer reviewe

Discovery of the giant squid Architeuthis in equatorial waters of the Atlantic Ocean

The discovery of the giant squid Architeuthis sp. outside the limits of the genus area known up to the present time is described. Possible causes for the presence of this squid in equatorial waters of the Atlantic are given

The biflagellate speratozoa of the squid genus Illex (Cephalopoda, Ommastrephidae): morphology, activity and concentraton in spermatophores

The typical biflagellate spermatozoa were found in all three species of the squid genus Illex, the most primitive genus in the family Ommastrphidae. This is the first finding of that phenomenon in Mollusca. Spermatozoa possess a slightly curved nucleus about 5.5 μm with tiny spheric acrosome, spur-like middle part and two flagella about 50 μm long. Keeping of spermatozoa in open air until destruction, in both sea and fresh water, and in pure alcohol showed a surprising stability of the nucleus shape. Spermatozoa with spheric nucleus habe been found in some preserved samples. This was probably an artifact of preservation, caused by the occasional presence of some unknown admixture in formalin solution which provoked a loss of osmotic stability. The spermatozoon velocity was 130-140 μm/sec which is similar to the maximum value registered in animals. The concentration of spermatozoa in spermatophores was 10.8-17.5 mln/mm³. The effective production of gametes packed in spermatophores was 50-100 billion (100-200 mln/g) in l. argentinus with mantle length (ML) 250-270mm