Size structure, age, and growth of the blue shark, Prionace glauca (Linnaeus, 1758) in southern Brazil DOI
Raquel Márquez, Rodrigo Barreto, Luís Gustavo Cardoso

et al.

Journal of Fish Biology, Journal Year: 2024, Volume and Issue: 105(1), P. 46 - 58

Published: April 15, 2024

Abstract The blue shark is a highly migratory species with worldwide distribution, making it susceptible to multiple fishing fleets across the globe. In southern Brazil, an important target, comprising up 40% of total biomass landed by commercial surface longline fleet. This study aims contribute better understanding how uses region and update its life‐history information available for future assessments. Over five consecutive years (2018–2022) landings onboard monitoring, we gathered size data vertebral samples describe composition in region, as well seasonal interannual variability estimated parameters. results showed that Brazil mainly inhabited large juvenile males arrive during winter (July–September) stay until spring (October–December), when their frequency decreases. Small adult are present throughout year but higher frequencies summer. A small number females summer, which decreases austral autumn winter. Some presence each life stage was observed among years. parameters were follows: L ∞: 255.02 cm fork length (FL), k : 0.20, 0 :35.68 FL males; 246.47 FL, 0.23, :36.77 females; 269.58 0.18, :36.19 pooled sexes. However, values must be cautiously interpreted, obtained cannot construed representative entire harvested stock due lack consistent some stages region.

Language: Английский

Phylogenetic analysis of viviparity, matrotrophy, and other reproductive patterns in chondrichthyan fishes DOI
Daniel G. Blackburn, Daniel F. Hughes

Biological reviews/Biological reviews of the Cambridge Philosophical Society, Journal Year: 2024, Volume and Issue: 99(4), P. 1314 - 1356

Published: April 1, 2024

ABSTRACT The reproductive diversity of extant cartilaginous fishes (class Chondrichthyes) is extraordinarily broad, reflecting more than 400 million years evolutionary history. Among their many notable specialisations are viviparity (live‐bearing reproduction) and matrotrophy (maternal provision nutrients during gestation). However, attempts to understand the evolution these traits have yielded highly discrepant conclusions. Here, we compile analyse current knowledge on in Chondrichthyes with particular foci frequency, phylogenetic distribution, directionality changes modes reproduction. To characterise transformations, amassed largest empirical data set parameters date covering nearly 800 species analysed it via a comprehensive molecular‐based phylogeny. Our reconstructions indicated that ancestral pattern for ‘short single oviparity’ (as found holocephalans) which females lay successive clutches (broods) one or two eggs. Viviparity has originated at least 12 times, 10 origins among sharks, batoids, (based published evidence) another potential origin fossil holocephalan. Substantial evolved six including placentotrophy, three separate oophagy (egg ingestion), histotrophy (uptake uterine secretions). In clades, placentation was replaced by histotrophy. Unlike past reconstructions, our analysis reveals no evidence ever reverted oviparity this group. Both arisen variety sequences. addition, given rise distinct egg‐laying patterns increased clutch (brood) size and/or involved deposition eggs advanced stages development. Geologically, oviparous arose Paleozoic. Most Mesozoic, while few represented low taxonomic levels Cenozoic origin. Coupled other recent work, review points way towards an emerging consensus chondrichthyans offering basis future functional analyses. This also contributes conservation efforts highlighting taxa whose reflect distinctive trajectories deserve special protection further investigation.

Language: Английский

Citations

11

Global habitat predictions to inform spatiotemporal fisheries management: Initial steps within the framework DOI Creative Commons
Heather D. Bowlby, Jean‐Noël Druon, Jon López

et al.

Marine Policy, Journal Year: 2024, Volume and Issue: 164, P. 106155 - 106155

Published: April 29, 2024

Tuna Regional Fishery Management Organizations (tRFMOs) are increasingly interested in spatiotemporal management as a tool to reduce interaction rates with vulnerable species.We use blue shark (Prionace glauca) case study demonstrate the critical first steps implementation process, highlighting how predictions of global habitat for life stages can be transformed into publicly-accessible spatial bycatch mitigation tool.By providing examples possible goals and an associated threshold identify essential habitats, we show these key areas represent relatively low percentage oceanic area on monthly basis (16-24% between 50 • S 60 N), yet have high potential protection efficiency (~ 42%) if fishing effort is redistributed elsewhere.While has demonstrable sharks effectively mitigate mortality sensitive stages, inherent challenges sequential that require careful consideration by tRFMOs work proceeds.We also discuss our single-species framework could easily extended multispecies approach assigning relative conservation risk before layering model integrated analysis.Such broader application address related reducing ecosystem effects pave way efficient fisheries co-management using ecosystem-based approach.

Language: Английский

Citations

4

Blue shark (Prionace glauca) movements, habitat use, and vertical overlap with longline fishing gears in the southwestern Atlantic Ocean DOI
Federico Mas, Enric Cortés, Rui Coelho

et al.

Marine Biology, Journal Year: 2024, Volume and Issue: 171(5)

Published: March 28, 2024

Language: Английский

Citations

0

Size structure, age, and growth of the blue shark, Prionace glauca (Linnaeus, 1758) in southern Brazil DOI
Raquel Márquez, Rodrigo Barreto, Luís Gustavo Cardoso

et al.

Journal of Fish Biology, Journal Year: 2024, Volume and Issue: 105(1), P. 46 - 58

Published: April 15, 2024

Abstract The blue shark is a highly migratory species with worldwide distribution, making it susceptible to multiple fishing fleets across the globe. In southern Brazil, an important target, comprising up 40% of total biomass landed by commercial surface longline fleet. This study aims contribute better understanding how uses region and update its life‐history information available for future assessments. Over five consecutive years (2018–2022) landings onboard monitoring, we gathered size data vertebral samples describe composition in region, as well seasonal interannual variability estimated parameters. results showed that Brazil mainly inhabited large juvenile males arrive during winter (July–September) stay until spring (October–December), when their frequency decreases. Small adult are present throughout year but higher frequencies summer. A small number females summer, which decreases austral autumn winter. Some presence each life stage was observed among years. parameters were follows: L ∞: 255.02 cm fork length (FL), k : 0.20, 0 :35.68 FL males; 246.47 FL, 0.23, :36.77 females; 269.58 0.18, :36.19 pooled sexes. However, values must be cautiously interpreted, obtained cannot construed representative entire harvested stock due lack consistent some stages region.

Language: Английский

Citations

0