Reproduction of blacknose shark (Carcharhinus acronotus) in coastal waters off northeastern Brazil

The blacknose shark, Carcharhinus acronotus, is a relatively small carcharinid, typically inhabiting continental shelf areas in the western Atlantic Ocean, from North Carolina throughout the Gulf of Mexico (Bigelow and Schroeder, 1948) and along the South American coast to Rio de Janeiro (Compagno, 1984). The abundance of this shark in nearshore areas throughout its distribution makes it accessible to commercial fishing, mainly from inshore hook-and-line and gill-net fisheries (Trent et al., 1997; Mattos and Hazin1)

Global collision-risk hotspots of marine traffic and the world’s largest fish, the whale shark

© The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Womersley, F. C., Humphries, N. E., Queiroz, N., Vedor, M., da Costa, I., Furtado, M., Tyminski, J. P., Abrantes, K., Araujo, G., Bach, S. S., Barnett, A., Berumen, M. L., Bessudo Lion, S., Braun, C. D., Clingham, E., Cochran, J. E. M., de la Parra, R., Diamant, S., Dove, A. D. M., Dudgeon, C. L., Erdmann, M. V., Espinoza, E., Fitzpatrick, R., González Cano, J., Green, J. R., Guzman, H. M., Hardenstine, R., Hasan, A., Hazin, F. H. V., Hearn, A. R., Hueter, R. E., Jaidah, M. Y., Labaja, J., Ladinol, F., Macena, B. C. L., Morris Jr., J. J., Norman, B. M., Peñaherrera-Palmav, C., Pierce, S. J., Quintero, L. M., Ramırez-Macías, D., Reynolds, S. D., Richardson, A. J., Robinson, D. P., Rohner, C. A., Rowat, D. R. L., Sheaves, M., Shivji, M. S., Sianipar, A. B., Skomal, G. B., Soler, G., Syakurachman, I., Thorrold, S. R., Webb, D. H., Wetherbee, B. M., White, T. D., Clavelle, T., Kroodsma, D. A., Thums, M., Ferreira, L. C., Meekan, M. G., Arrowsmith, L. M., Lester, E. K., Meyers, M. M., Peel, L. R., Sequeira, A. M. M., Eguıluz, V. M., Duarte, C. M., & Sims, D. W. Global collision-risk hotspots of marine traffic and the world’s largest fish, the whale shark. Proceedings of the National Academy of Sciences of the United States of America, 119(20), (2022): e2117440119, https://doi.org/10.1073/pnas.2117440119.Marine traffic is increasing globally yet collisions with endangered megafauna such as whales, sea turtles, and planktivorous sharks go largely undetected or unreported. Collisions leading to mortality can have population-level consequences for endangered species. Hence, identifying simultaneous space use of megafauna and shipping throughout ranges may reveal as-yet-unknown spatial targets requiring conservation. However, global studies tracking megafauna and shipping occurrences are lacking. Here we combine satellite-tracked movements of the whale shark, Rhincodon typus, and vessel activity to show that 92% of sharks’ horizontal space use and nearly 50% of vertical space use overlap with persistent large vessel (>300 gross tons) traffic. Collision-risk estimates correlated with reported whale shark mortality from ship strikes, indicating higher mortality in areas with greatest overlap. Hotspots of potential collision risk were evident in all major oceans, predominantly from overlap with cargo and tanker vessels, and were concentrated in gulf regions, where dense traffic co-occurred with seasonal shark movements. Nearly a third of whale shark hotspots overlapped with the highest collision-risk areas, with the last known locations of tracked sharks coinciding with busier shipping routes more often than expected. Depth-recording tags provided evidence for sinking, likely dead, whale sharks, suggesting substantial “cryptic” lethal ship strikes are possible, which could explain why whale shark population declines continue despite international protection and low fishing-induced mortality. Mitigation measures to reduce ship-strike risk should be considered to conserve this species and other ocean giants that are likely experiencing similar impacts from growing global vessel traffic.Funding for data analysis was provided by the UK Natural Environment Research Council (NERC) through a University of Southampton INSPIRE DTP PhD Studentship to F.C.W. Additional funding for data analysis was provided by NERC Discovery Science (NE/R00997/X/1) and the European Research Council (ERC-AdG-2019 883583 OCEAN DEOXYFISH) to D.W.S., Fundação para a Ciência e a Tecnologia (FCT) under PTDC/BIA/28855/2017 and COMPETE POCI-01–0145-FEDER-028855, and MARINFO–NORTE-01–0145-FEDER-000031 (funded by Norte Portugal Regional Operational Program [NORTE2020] under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund–ERDF) to N.Q. FCT also supported N.Q. (CEECIND/02857/2018) and M.V. (PTDC/BIA-COM/28855/2017). D.W.S. was supported by a Marine Biological Association Senior Research Fellowship. All tagging procedures were approved by institutional ethical review bodies and complied with all relevant ethical regulations in the jurisdictions in which they were performed. Details for individual research teams are given in SI Appendix, section 8. Full acknowledgments for tagging and field research are given in SI Appendix, section 7. This research is part of the Global Shark Movement Project (https://www.globalsharkmovement.org)

Diving into the vertical dimension of elasmobranch movement ecology

Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand their ecological roles and exposure to anthropogenic pressures. To date, comparative studies among species at global scales have mostly focused on horizontal movements. Our study addresses the knowledge gap of vertical movements by compiling the first global synthesis of vertical habitat use by elasmobranchs from data obtained by deployment of 989 biotelemetry tags on 38 elasmobranch species. Elasmobranchs displayed high intra- and interspecific variability in vertical movement patterns. Substantial vertical overlap was observed for many epipelagic elasmobranchs, indicating an increased likelihood to display spatial overlap, biologically interact, and share similar risk to anthropogenic threats that vary on a vertical gradient. We highlight the critical next steps toward incorporating vertical movement into global management and monitoring strategies for elasmobranchs, emphasizing the need to address geographic and taxonomic biases in deployments and to concurrently consider both horizontal and vertical movements

Physiculus Kaup 1858

Genus <i>Physiculus</i> Kaup <p> <i>Physiculus</i> Kaup, 1858: 88. Type species: <i>Physiculus dalwigki</i> Kaup, 1858: 88, by monotypy. The diagnosis and description of the genus follow Paulin (1989), Paulin & Matallanas (1990), Trunov (1991), and Shcherbachev (1993).</p> <p> <b>Diagnosis.</b> Morid fishes with ventral light organ in advance of anus; chin barbel present; vomerine teeth absent.</p> <p> <b>Description.</b> Morid fishes with elongated somewhat compressed body. Chin barbel present, eventually much reduced (as in <i>P. microbarbata</i>). Two dorsal and one anal fin of uniform height, separated from the caudal fin that is slightly rounded to rounded (the new species herein described has the posterior border of the caudal fin often rounded, as well as <i>P. maslowskii</i>). Snout broad, obtusely rounded, not projecting beyond mouth. Scales small, cycloid, covering entire body and head, extending or not onto snout, gular region, and fins. Ventral fins with outermost rays filamentous. Circular luminescent organ on midline of belly, connected to anus by a duct; this organ lies in body wall between ventral-fin bases and anus, it is externally obvious as a circular, scaleless, dermal fossa. Teeth in a brush-like band and variable: equal to sub-equal sized, or with outer ones slightly larger, or with distinct separation between larger and smaller teeth. No teeth on vomer.</p>Published as part of <i>Pires, Alessandra M. A., Carvalho-Filho, Alfredo, Ferreira, Rômulo C. P., Viana, Danielle, Nunes, Diogo & Hazin, Fabio H. V., 2019, Review of the Brazilian species of Physiculus (Gadiformes: Moridae), with description of a new species from Saint Peter and Saint Paul Archipelago, equatorial Atlantic, pp. 67-80 in Zootaxa 4671 (1)</i> on page 69, DOI: 10.11646/zootaxa.4671.1.5, <a href="http://zenodo.org/record/3450252">http://zenodo.org/record/3450252</a&gt

Physiculus karrerae Paulin 1989

<i>Physiculus karrerae</i> Paulin, 1989 <p>Table 2 and 3.</p> <p> <b>Diagnosis.</b> This species differs from all other Atlantic species, except <i>P. helenaensis, P. dalwigki</i> and <i>P. kaupi,</i> by the smaller scales in longitudinal series and consequently larger number (134–160 vs.70–130). From <i>P. helenaensis</i>, which does not have the number of scales in longitudinal series known to date, it differs by the discontinuous lateral line (vs. continuous to posterior part of body). From <i>P. dalwigki,</i> which has 119–135 longitudinal series of scales, it differs by the greater distance of the light organ to interventral line (8.2–16.8 Inv-af vs. 0–2.4 Inv-af). And from <i>P. kaupi</i>, it differs by the absence of scales on vertical fins and gular region (vs. scales present on vertical fins and gular region), according to Paulin (1989, 1990), Trunov (1991), Shcherbachev (1993), Anderson & Tweddle (2002), and our examination of vouchers of this species, and of the new species herein described.</p> <p> <b>Brief Description.</b> Light organ large, 10.0–22.0% InV-af and placed closer to interventral line than anus; distance from interventral line to anterior margin of light organ 8.2–16.8% InV-af; distance from posterior margin of light organ to anterior margin of anus 13.3–17.6% InV-af; teeth subequal. Continuous tube of lateral line reaching beyond origin of second dorsal fin, almost to tenth second dorsal-fin ray. No scales on vertical fin membranes, gular region, tip of snout, and around nostrils. Nostrils contiguous, the anterior covered by a skin flap, the posterior open, oval, with a short anterior projection. Gill rakers long, slender, 1–3 + 7–9. Upper jaw reaching to below middle of the orbit; orbit 24–29% of head length. Dorsal-fin rays 7–8, 64–76; anal-fin rays 68–81; pectoral-fin rays 24–27; scales in longitudinal series 134–160; scales between base of first dorsal fin and lateral line 14–20; vertebrae 56–59. Color of preserved specimens: head and body brown, smaller specimens light pinkish tan on head and body; abdominal region bluish; gular region, branchiostegal membranes, lips, anterior margin of orbit, base of pectoral fin and tips of vertical fins dark brown; light organ dark brown to blackish. Color of fresh specimen: head and body uniform reddish brown; abdominal region dark bluish black often over whitish background; fins margins and lips dark brown; light organ dark brown to blackish. Maximum known size 274 mm SL.</p> <p> <b>Distribution.</b> Tropical Atlantic Ocean, from Gulf of Mexico, Bermuda, off North Carolina, and Caribbean Sea to southern Brazil, and from Saint Helena Island, Tristan da Cunha Island, and Walvis Ridge (Eastern Atlantic). Depth range 50–800m, usually 200–500m, shallower (50–150m) waters of Tristan da Cunha (Paulin, 1989; Edwards, 1990; Trunov, 1991; Andrew <i>et al</i>., 1995; Iwamoto and Cohen, 2002; Smith-Vaniz <i>et al</i>., 1999).</p>Published as part of <i>Pires, Alessandra M. A., Carvalho-Filho, Alfredo, Ferreira, Rômulo C. P., Viana, Danielle, Nunes, Diogo & Hazin, Fabio H. V., 2019, Review of the Brazilian species of Physiculus (Gadiformes: Moridae), with description of a new species from Saint Peter and Saint Paul Archipelago, equatorial Atlantic, pp. 67-80 in Zootaxa 4671 (1)</i> on page 70, DOI: 10.11646/zootaxa.4671.1.5, <a href="http://zenodo.org/record/3450252">http://zenodo.org/record/3450252</a&gt

Review of the Brazilian species of Physiculus (Gadiformes: Moridae), with description of a new species from Saint Peter and Saint Paul Archipelago, equatorial Atlantic

Pires, Alessandra M. A., Carvalho-Filho, Alfredo, Ferreira, Rômulo C. P., Viana, Danielle, Nunes, Diogo, Hazin, Fabio H. V. (2019): Review of the Brazilian species of Physiculus (Gadiformes: Moridae), with description of a new species from Saint Peter and Saint Paul Archipelago, equatorial Atlantic. Zootaxa 4671 (1): 67-80, DOI: https://doi.org/10.11646/zootaxa.4671.1.

Physiculus kaupi Poey 1865

Physiculus kaupi Poey, 1865 Table 2 and 3. Diagnosis. This species differs from all other Atlantic species of the genus, except P. cyanostropus, P. maslowskii, and P. microbarbata, by the presence of scales on vertical fins and gular region and in having subequal rather than a graded series of teeth (graded in P. maslowskii, of which it also differs by the number of gill rakers, 2–3 + 5–10 vs. 4–5 + 9–12); from P. microbarbata it differs by the much longer chin barbel (4.3–6.2 in SL vs. 1.0); and from P. cyanostrophus it differs in all fins rays counts and by the higher number of scales between the first dorsal fin base and the lateral line (12–14 vs. 8), according to Paulin (1989, 1990), Trunov (1991), Anderson & Tweddle (2002), and our examination of vouchers of this species and of the new species herein described. Brief Description. Light organ moderately large 8.8–11.2% InV-af and placed slightly closer to interventral line than anus; distance from interventral line to anterior margin of light organ 19.5–22.2% InV-af; distance from posterior margin of light organ to anterior margin of anus 26.4–28.8% InV-af; teeth subequal. Continuous tube of lateral line reaching beyond second dorsal fin origin, almost to tenth dorsal-fin ray; scales present on gular region, rarely absent; small scales present on vertical fin membranes; no scales on tip of snout and around nostrils. Nostrils contiguous, each covered by a skin flap. Gill rakers moderate, blunt or slightly club shaped, spiny, 2–3 + 5–10. Upper jaw reaching below almost to the posterior border of pupil; orbit 22–28% in head length. Dorsal-fin rays 11–12, 57–66; anal-fin rays 62–69; pectoral-fin rays 27–31; scales in longitudinal series 120–140; scales between base of first dorsal fin and lateral line 12–14; vertebrae 52–54. Color of preserved specimens. Head and body light pinkish tan to grey; abdominal region bluish white to purple; pores of lateral line on the posterior part of body usually as dark spots over pale background; branchiostegal membranes, lips, anterior margin of orbit, upper and lower base of pectoral fins, upper snout, and tips of vertical fins dark brown; light organ dark brown to blackish. Color of fresh specimens: head and body uniform pinkish tan; abdominal region iridescent bluish often over whitish background; golden tinge on body sides; pores of lateral line on the posterior part of body usually dark; fins margins and lips dark brown; pelvic fins pinkish orange; light organ dark brown to blackish. Two of the fresh examined specimens were almost dark brown overall with a golden tinge on upper anterior body and head, the belly somewhat washed with white and fins borders black. These fishes become darker than the lighter morphs when preserved, the pores of lateral lines not conspicuous. Maximum known size 275.3 mm SL (DBUFC 74) collected off Ceará, Brazil. Distribution. Tropical Western Atlantic, from Caribbean Sea (Cuba, Nicaragua) to Southern Brazil. Depth range 200–500 m (Paulin, 1989; Jordan and Evermann, 1898; Iwamoto and Cohen, 2002; Figueiredo et al., 2002; Paiva et al., 2011).Published as part of Pires, Alessandra M. A., Carvalho-Filho, Alfredo, Ferreira, Rômulo C. P., Viana, Danielle, Nunes, Diogo & Hazin, Fabio H. V., 2019, Review of the Brazilian species of Physiculus (Gadiformes: Moridae), with description of a new species from Saint Peter and Saint Paul Archipelago, equatorial Atlantic, pp. 67-80 in Zootaxa 4671 (1) on pages 70-71, DOI: 10.11646/zootaxa.4671.1.5, http://zenodo.org/record/345025

Physiculus fulvus Bean 1884

<i>Physiculus fulvus</i> Bean, 1884 <p>Tables 2 and 3.</p> <p> <b>Diagnosis.</b> This species differs from all other Atlantic species of the genus in having relatively large scales in longitudinal series (70–84 vs. 90–189), according to Paulin (1989, 1990), Trunov (1991), Anderson & Tweddle (2002), our examination of vouchers of this species, and of the new species herein described.</p> <p> <b>Brief Description.</b> Light organ moderately large 7.5–13.2% InV-af and placed midway between interventral line and anus; distance from interventral line to anterior margin of light organ 17.6–25.6% InV-af; distance from posterior margin of light organ to anterior margin of anus 21.1–24.5% InV-af; teeth subequal. Continuous tube of lateral line not reaching origin of second dorsal fin. No scales on vertical fin membranes, gular region, tip of snout, and around nostrils. Nostrils contiguous, each one in a short tube without a skin flap. Gill rakers moderately long, slender, 2–4 + 8–11. Upper jaw reaching below posterior margin of pupil. Orbit 24–28% in head length. Dorsal-fin rays 9–12, 57–61; anal-fin rays 59–68; pectoral-fin rays 21–26; scales in longitudinal series 70–84, scales between base of first dorsal fin and lateral line 6–7; vertebrae 47–50.</p> <p> <i>Color of preserved specimens</i>. Head and body pinkish tan to light yellowish brown; abdominal region bluish to purplish (often brown in long preserved specimens), with silvery tinge extending onto sides of body and head; axil of pectoral fin dark brown; margins of anal and dorsal fins dark brown to black; external border of lips and gular region dark brown; a dark brown blotch on sub-operculum; light organ dark brown to blackish. Maximum known size 133 mm SL.</p> <p> <b>Distribution.</b> Temperate and tropical western Atlantic Ocean, from southern Canada (43 o 16´N and 60 o 58´W) and Cape Cod (USA), to Rio Grande do Norte, in the “hump” of Brazil, including the Gulf of Mexico, the Bahamas and the Caribbean Sea. Depth range 68-800 m, usually bellow 100 m. (Bean, 1884; Jordan and Evermann, 1898; Arai, 1983; Scott & Scott, 1988; Paulin, 1989; McEachran and Fechhelm, 1998; Klein-MacPhee, 2002; Iwamoto and Cohen, 2002; Oliveira <i>et al</i>., 2015; Moore <i>et al</i>., 2015.</p>Published as part of <i>Pires, Alessandra M. A., Carvalho-Filho, Alfredo, Ferreira, Rômulo C. P., Viana, Danielle, Nunes, Diogo & Hazin, Fabio H. V., 2019, Review of the Brazilian species of Physiculus (Gadiformes: Moridae), with description of a new species from Saint Peter and Saint Paul Archipelago, equatorial Atlantic, pp. 67-80 in Zootaxa 4671 (1)</i> on pages 69-70, DOI: 10.11646/zootaxa.4671.1.5, <a href="http://zenodo.org/record/3450252">http://zenodo.org/record/3450252</a&gt