Search

AFS Global Conference, 22-23 October 2020, online

ICES Annual Science Conference, 9-12 September 2019, Gothenburg, Sweden, Cephalopods are short-lived fast growing species which are highly sensitive to environmental variation, as reflected in wide year-to-year fluctuations in abundance. Understanding the relative importance of environmental variation and fishing mortality in determining stock trajectories is essential to underpin appropriate management measures and support sustainable exploitation of these species. Over three decades ICES WGCEPH has reported on patterns and trends in cephalopod landings in the ICES area but there has been no comprehensive analysis of patterns and trends. We assembled data series on loliginid squid, ommastrephid squid, octopus and cuttlefish from landings (where possible considering landings per unit effort) and survey catches. For most series it is not possible to be sure of the cephalopod species involved so the main analysis is at family level. We used a combination of standard time series analysis, dynamic factor analysis, generalised additive models and generalised additive mixed models to analyse patterns and trends in these datasets and to try to identify the underlying causes of abundance variation and thus provide a basis for deigning management measures. We quantified common trends so as to assess whether cephalopods are generally increasing in abundance. We also separated out the variation related to taxon, country and gear-type, and compared commercial fishery and research survey data. For survey data we examined seasonal and regional variation in abundance. We tested whether observed interannual variation and trends were related to largescale environmental variation (as captured by the NAO and similar indices) and to fishery catches in the previous year

Poster.-- ICES Annual Science Conference, 9-12 September 2019, Gothenburg, Sweden

10 pages, 3 figures, 2 tables, The oegopsid squid family Onychoteuthidae was recently revised based on morphology, but sufficient material for a complementary molecular analysis has not been available until now. In the present study, over 250 sequences of cytochrome c oxidase subunit I (COI) and 16S rRNA for 222 individuals were analysed to create a combined phylogeny for the family. Results support monophyly for the family and all seven onychoteuthid genera (including Moroteuthopsis, established herein as the senior genus name for species formerly attributed to Kondakovia); 29 genetically distinct species were recovered, with the BIN (Barcode Index Number) analysis for COI showing good congruence overall with morphological species groupings. No sequences were available for five additional known species, making the total family diversity likely to exceed 34 species. Seven of the BINs formed in this study appear to represent undescribed taxa, suggesting that even in this relatively well-studied family, much additional work remains before a comprehensive understanding of the diversity and evolutionary relationships for the Onychoteuthidae can be achieved, This work was supported by the New Zealand government under “Coasts & Oceans” core funding from the Ministry of Business, Innovation and Employment (project: Food-web dynamics of New Zealand marine ecosystems)

Laptikhovsky, Vladimir, Reyes, Pablo R. (2009): Distribution and reproductive biology of a subantarctic deep-sea lobster, the Patagonian lobsterette Thymops birsteini (Zarenkov and Semenov, 1972) (Decapoda, Astacidea, Nephropidae). Journal of Natural History 43 (1-2): 35-46, DOI: 10.1080/00222930802567099, URL: http://dx.doi.org/10.1080/00222930802567099

Habitats and life cycle strategies of nektonic squid of genera Allote!llhis, Loligo, Illex, Todarodes, Todaropsis, and Sthenoteuthis, occurring off the Northwest African coast are described. The teuthofauna of the region consists of a mixture of boreal and tropical species, each associated with its specific water mass. Both boreal and tropical squid inhabit the ecotone zone, the main features of their life styles are common to that of the central part of their species ranges. Boreal species inhabit cold waters of either Sahara or Canary Currents, or inshore upwelling waters. They have the winter peak of the spawning. Species, which ranges extend into tropics, inhabit waters of tropical origin and tends to stay off the upwelling activities. As their southern counterparts, these species have a spring-summer peak in their spawning. In squid assemblage, fecundity increased about ten-folds at each step from the inner shelf to the shelf break and slope, and then to the open ocean. Egg size decreased in the same direction. The possible reason is an increase in mortality at early stages that forces species to produce more eggs at cost of egg size and offspring quality.

A total of 24 female Abralia verany specimens, with a mantle length between 26-47 mm, were investigated. The mean potential fecundity (PF) and mean relative fecundity (RF) of ovaries were calculated as 26584 eggs and 4379 eggs g-1, respectively. The mean egg number determined in the oviduct was 251. Diameters of ripe eggs in the oviduct were approximately 1.01 mm. According to the findings given above the PF values of A. verany in the eastern Mediterranean are higher than the ones off northwest Africa. Se estudiaron un total de 24 hembras de Abralia verany, entre 26-47 mm de longitud del manto. La fecundidad potencial media (PF) y la fecundidad relativa media (RF) de los ovarios se calcularon como 26584 huevos y 4379 huevos g-1 respectivamente. El número medio de huevos en el oviducto fue de 251. El diámetro de los huevos maduros en el oviducto fue de 1.01 mm aproximadamente. Según los resultados obtenidos los valores de PF de A. verany del Mediterráneo oriental son más altos que los del noroeste de Africa.

An investigation was carried out during the Illex argentinus trawl fishery (January-July) in the fishery regions of 42 °S and 45-47 °S off the Exclusive Economic Zone of Argentina between 1985 and 1990. Statoliths of 5,232 squid were sampled and processed to study age and growth patterns in squid, hatched in different months. Among squid of similar ages (within an age interval from 180 to 300 days), the May-hatched squid were the smallest while the September-hatched were largest. Growth rates of squid of the same hatching-months were significantly different according to year, but these differences were considerably smaller than those observed between various hatching-months within one year. The largest individuals at a given age were captured in 1990, and the smallest in 1985. Males and females became mature at age 220-320 and 210-360 days respectively. The maturation period lasts 1.5-2.5 months in males and 1 month in females. Early and late-maturing groups were observed within each hatching-month. The peak. of spawning was in July of 1984, 1986, 1987, in June of 1985 and in August of 1989.