‘Superbull’ males : what role do they play and what drives their appearance within the Doryteuthis gahi Patagonian Shelf population?

This work was funded by the Falkland Islands Government. Thanks are due to FCT/MCTES for financial support to CESAM (UID/AMB/50017/2019) through national funds and ERDF co-financing, under the Partnership Agreement for the PT2020 and Compete 2020 programs. This work was funded by the Falkland Islands Government. The study was conducted using E.U. Copernicus Marine Service Information. We are grateful to the scientific observers from the Falkland Islands fisheries department for sample collection and to the director of fisheries, John Barton, for supporting this work.Peer reviewedPublisher PD

Using statolith elemental signatures to confirm ontogenetic migrations of the squid Doryteuthis gahi around the Falkland Islands (Southwest Atlantic)

This work was supported by the Falkland Islands Government. We thank Dr. Simon Chenery and the British Geological Survey for assistance with the LA-ICP-MS analysis and training and use of their facilities. We are grateful to the scientific observers from the Falkland Islands Fisheries Department for sample collection. We thank the Director of Fisheries, John Barton, and the director of SAERI, Paul Brickle, for supporting this work. We thank Dr. Elena Ieno, Dr. Andreas Winter, Dr. Haseeb Randhawa and three anonymous reviewers for their helpful comments that greatly improved the manuscript.Peer reviewedPostprin

Size-dependent change in body shape and its possible ecological role in the Patagonian squid (Doryteuthis gahi) in the Southwest Atlantic

This study was supported by funding from the Falkland Islands Government. We are grateful to the scientific observers from the Falkland Islands Fisheries Department for sample collection and Beverley Reid for collecting traditional morphometric measurements and to three anonymous referees for their comments which greatly improved the manuscript. We thank the Director of Fisheries, John Barton, for supporting this work. The MASTS pooling initiative (Marine Alliance for Science and Technology for Scotland, funded by the Scottish Funding Council and contributing institutions; grant reference HR09011) is gratefully acknowledged. Thanks are due to FCT/MCTES for financial support to CESAM (UID/AMB/50017/2019) through national funds and ERDF co-financing, under the Partnership Agreement for the PT2020 and Compete 2020 programsPeer reviewedPostprin

World squid fisheries

Peer reviewedPublisher PD

Promoting higher added value to a finfish species rejected to sea

This project aimed to the development of the research and the technology necessary to promote higher added value to fishing activity. This is to be achieved by obtaining profit from a finfish species (“Rockcod”, Patagonotothen spp.) not known to consumers and currently discarded by the EU fishing fleet operating in the South West Atlantic, in order to supply the EU seafood industry with a good quality raw material for human food manufacturing. Use of this species, caught as a by-catch in the existing fisheries targeting hakes and cephalopods, should also increase the profitability of the fleet, contribute to maintaining employment and help to counterbalance the negative effects of fishing activity and discards in the ecosystem. The main scientific-technological objectives and expected achievements were the following: - Description of the fisheries - Improved knowledge of the biology of the species - Biomass assessment - Estimation of catches and discards - Analysis of the spatial and temporal distribution of the resource. Fishery forecasting and testing - Sensorial, Microbiological, Nutritional and Biochemical Evaluation of Rock cod - Development of the technical modifications on board commercial vessels - Development of new processed products from frozen Rock codEuropean Commission Cooperative Research (CRAFT

Intrapopulation structure of winter-spawned Argentine shortfin squid, Illex argentinus (Cephalopoda, Ommastrephidae), during its feeding period over the Patagonian Shelf

Stock structure dynamics of the important commercial squid Illex argentinus were studied by using bio-logical data from about 25 thousand squid caught January–April 1991 by Russian trawlers in three fishery regions: 51–52°S; 47–49°S within the exclusive economic zone of Argentina (EEZA); and 45–47°S outside the EEZA. A total of 2664 statoliths were read to prepare age-length keys for each 10-day interval of the period studied. It was found that between January and April, the Patago-nian shelf south of 45°S was a feeding ground of two intraspecific groups of winter-hatched I. argentinus: a shelf group that matured at medium sizes (ShG) and a slope group that matured at large sizes (SlG). After massive immi-gration of I. argentinus from the north in January–February into the two fish-ery regions within 45–49°S, the stock structure remained rather stable until April, composed predominantly of June- and July-hatched squid. Squid grow and mature rapidly, and males mature at younger ages (from one to two months) than do females. During feeding, some redistribution of the stock was observed: maturing and mature SlG squid (mainly females) tended to shift from the shelf (130–150 m depth) in a northeast direc-tion and concentrate over the shelf edge (160–170 m depth). In April, mature SlG squid began to shift to the continental slope around 45–47°S and migrated to depths >600 m where they then mixed with schools of SlG squid that had fed in the region 51–52°S and that were already migrating northwards along the slope. ShG squid remained on the shelf and made their prespawning northward migrations along the shelf edge

Age, growth and maturation of the squid Enoploteuthis leptura (Oegopsida: Enoploteuthidae) from the central-east Atlantic

Fifty-nine specimens of the tropical epipelagic eno-ploteuthid Enoplotcuthis leptura were collected in the central-east Atlantic between 1986–1988. Statoliths were extracted from all specimens (mantle length (ML) 4.1–92 mm) and processed under the statolith ageing technique. The characteristic feature of statolith morphology in E. leptura is a sculpture of the rostrum, which is covered by numerous tiny spines and knobs. In the ground statolith it was possible to distinguish four main growth zones consisting of narrow growth increments like those in other squids studied. Allometric growth of statoliths versus ML is negative. E. leptura is a short-lived squid with a half-year life span. Growth rates of E. leptura are high at juvenile stage (instantaneous rate of growth (G) of body weight (BW) 0.04–0.06). An early maturation of males (at age 45–60 days) and females (at 80–90 days) causes a sharp decrease of somatic growth of E. leptura, and mature squid have low growth rates (G of BW - 0.OO3-O.0O5). Spawning takes place between January and September with two peaks: in January and in June-July

GETTING HOOKED: THE ROLE OF A U-SHAPED BODY CHAMBER IN THE SHELL OF ADULT HETEROMORPH AMMONITES

ABSTRACT Cretaceous heteromorph ammonites of the suborder Ancyloceratina had a striking ontogenetic change in their shell shape. Juveniles had virtually all possible types of coiling of their shells, ranging from regular planispiral and orthoconic to torticonic, hamitoconic and gyroconic. The adults uncoiled the last whorl of their shell forming a U-shaped recurved body chamber with the aperture facing upward. Examination of ribbing pattern and its resolution in various parts of the living chamber in 11 species revealed that the ribs were less developed and had some traces of wear on the inner surface of the hooked chamber, being well developed both on the lateral and outer lower parts. This could indicate that the adult animals were semi-loosely hooked (Ancyloceras, Macroscaphites) or permanently clipped (Scaphites, Hoploscaphites) onto either horizontal or upwardly angled stipes of non-calcified algal macrophytes or branched animals. Comparison of the adult mode of life with those of modern cephalopods suggested that ammonites of the suborder Ancyloceratina had developed a stationary brooding phase that could have several ecological advantages over free-swimming monomorph ammonites

Statolith microstructure and maximum age of the sepiolid Rossia pacifica (Cephalopoda, Sepioidea) in the northern part of the North Pacific

Statolith microstructure was studied in eight specimens of the boreal sepiolid Rossia pacifica (mantle length ranging from 45to 90mm) caught on the continental slope of Northwest Bering Sea. Growth increments were presented in all ground statoliths and were narrow and uniform width (average 3.2 - 3.3µm). They were grouped into inner opaque and outer translucent growth zones. The total number of growth increments within the statoliths of mature males (75-78) was lower than of mature females (95-117 increments). Assuming growth increments to be laid down daily, the life span from hatching to death of R. pacifica in the Bering Sea may be 4-5 months

Ontogenetic changes in morphometric and reproductive indices of the squid Gonatus fabricii (Oegopsida, Gonatidae) in the Norwegian Sea

Ontogenetic changes in morphometric and reproductive indices were studied using 166 individuals of the arctic gonatid squid Gonatus fabricii (7.3–322 mm pen length) collected in the southern part of the Norwegian Sea. Body proportions and consistency of the mantle and fins did not change in maturing and mature males. In contrast, during maturation the females first lost their tentacles, then the horny rings of their 4th arm suckers, and the muscular part of their body turned watery and gelatinous. Unlike most squid, G. fabricii females start mating at maturity stage III, and all but one female at stage IV had mated, as well as all spent females. Females had high values of both gonadosomatic index and maturity indices compared to those of the North Pacific gonatids, whereas gonadosomatic index values of males were low, probably due to slow functioning of both testis and spermatophoric gland, and long accumulation of spermatophores in the Needham's sac. It is suggested that the breakdown of female body tissues is an adaptation for a deepwater bathypelagic “brooding” of the negatively buoyant egg-mass caused by the high specific density of the secretion from the nidamental glands in gonatids