Reproductive biology of the silky shark Carcharhinus falciformis (Müller & Henle, 1839) in waters off Côte d’Ivoire (West Africa)
Since 2008, the quantity and size of silky shark, Carcharhinus falciformis decrease drastically in catches of artisanal driftnet fishery operating in the coastal waters off Côte d’Ivoire. The objective of this study was to describe the reproductive biology of this species, based on 336 specimens (162 males and 174 females). The total length (TL) of males and female ranged from 81–242 and 79–254 cm respectively. The sex ratio was 0.89:1 (M:F) and 0.93:1 (M:F) in embryos and adults respectively. Males of >180 cm had calciﬁed clasper (17–35 cm) whereas females of >190 cm had oviduct gland length of 18–47 mm. The estimated length at first maturity was 182.8 cm for males and 195.2 cm for females. The range in litter size of three gravid females was 7–9, with an average of 8 embryos of 52–54.5 cm TL were collected in August and December. However, the absence of neonates and scars on females' body, as well as ovulating and differentiating females in catches does not allow a clear determination of its reproductive period in Ivorian waters and therefore, additional research including histological analysis is necessary to better understand the process of spawning of silky shark.
Bonfil R (2008) The biology and ecology of the silky shark, Carcharhinus falciformis. In: Camhi M, Pikitch EK, Babcock EA (Eds) Sharks of the open ocean. Biology Fisheries and Conservation, Blackwell Science. pp. 114–127.
Campana SE, Joyce W, Manning MJ (2009) Bycatch and discard mortality in commercially caught blue sharks Prionace glauca assessed using archival satellite pop-up tags. Marine Ecology Progress Series 387: 241–253.
Chia YL, Xing-Han W, Liu V, Yin S, Sheng-Ping W, Wen-Pei Sai T (2021) Catch rates and distribution pattern of the silky shark, Carcharhinus falciformis, caught by the Taiwanese large-scale longline fishery in the Indian Ocean. Journal of Marine Science and Technology 8(29): 674–684.
Clarke SC, Harley SJ, Hoyle SD, Rice JS (2012) Population trends in Pacific Oceanic sharks and the utility of regulations on shark finning. Conservation Biology 27(1): 197–209.
Clavareau L, Sabarros PS, Escalle L, Bach P, Abascal FJ, ... Mérigot B (2020) Elasmobranch bycatch distributions and mortality: insights from the European tropical tuna purse-seine fishery. Global Ecology and Conservation 24: e01211.
Compagno LJV (1984) Sharks of the world. An annotated and illustrated catalogue of shark species known to date. Part 1- Hexanchiformes to Lamniformes: viii, 1-250. Part 2-Carcharhiniformes: x, 251-655. Fisheries Synopsis 125(4): 1–655.
Cortés E, Arocha LF, Beerkircher F, Carvalho A, Domingo M, ... Ribera Simpfendorfer C (2010) Ecological risk assessment of pelagic sharks caught in Atlantic pelagic longline fisheries. Aquatic Living Resources 23(1): 25–34.
Cortés E, Brown CA, Beerhircher LR (2007) Relative abundance of pelagic sharks in the western North Atlantic Ocean, including the Gulf of Mexico and Caribbean Sea. Gulf and Caribbean Research 19(2): 37–52.
Curnick DJ, Andrzejaczek S, Jacoby DMP, Coffey DM, Carlisle AB, ... Collen B (2020) Behavior and ecology of silky sharks around the Chagos archipelago and evidence of Indian Ocean wide movement front. Marine Science 7: 1–18.
Del Rosario RC (1998) Biology and fishery of silky shark Carcharhinus falciformis (Bibron, 1839) in Guatemala. Business Social Compliance Initiative (Bsci). Thesis, Universidad San Carlos de Guatemala, CEMA, Guatemala. pp. 74.
Escalle L, Gaertner D, Chavance P, Murua H, Pascual-Alayón PJ, ... Mérigot B (2019) Catch and bycatch captured by tropical tuna purse-seine fishery in whale and whale shark associated sets: comparison with free school and FAD sets. Biodiversity and Conservation 28: 467–499.
Forselledo R, Domingo A, Mas F, Miller P (2022) Silky shark. ICCAT manual. pp. 17.
Galván-Tirado F, Galván-Magaña F, Ochoa baez AI (2015) Reproductive biology of the silky shark Carcharhinus falciformis in the southern Mexican Paciﬁc. Journal of the Marine Biological Association of the United Kingdom 95(3): 561–567.
Ghorbel M, Jarboui O, Bradai MN, Bouain A (1996) Determination of size at first sexual maturity by a logistic function in Limanda limanda, Pagellus erythrinus and Scorpaena porcus. Bulletin of the National Institute of Marine Sciences and Technology 3: 24–27.
Grant MI, Smart JJ, White WT, Chin A, Baje L, Simpfendorfer CA (2018) Life history characteristics of the silky shark Carcharhinus falciformis from the central West Pacific. Marine and Freshwater Research 69: 562−573
Hall NG, Bartron C, White WT, Dharmadi A, Potter IC (2012) Biology of the silky shark Carcharhinus falciformis (Carcharhinidae) in the eastern Indian Ocean, including an approach to estimating age when timing of parturition is not well deﬁned. Journal of Fish Biology 80(5): 1320–1341.
Hazin FHV, Oliveira PGV, Macena BCL (2007) Aspects of the reproductive biology of the silky shark, Carcharhinus falciformis (Nardo, 1827), in the vicinity of Archipelago of Saint Peter and Saint Paul, in the Equatorial Atlantic Ocean. ICCAT. Collective Volume of Scientific Papers 60(2): 648–651.
Heupel MR, Carlson JK, Simpfendorfer CA (2007) Shark nursery areas: concepts, definition, characterization and assumptions. Marine Ecology Progress Series 337: 287–297.
Hoyos-Padilla M, Ceballos-Vazquez BP, Galvan-Magana F (2012) Reproductive biology of the silky shark Carcharhinus falciformis (Chondrichthyes: Carcharhinidae) off the west coast of Baja California Sur, Mexico. International Journal of Ichthyology 18: 15–24.
Hutchinson M, Coffey DM, Holland K, Itano D, Leroy B, ... Wren J (2019) Movements and habitat use of juvenile silky sharks in the Paciﬁc Ocean inform conservation strategies. Fisheries Research 210: 131–142.
IOTC (2013) Report of the sixteenth session of the IOTC scientific committee. Busan, Rep. of Korea, 2–6 December 2013. IOTC–2013–SC16–R[E]: 312 pp.
Joung SJ, Chen CT, Lee HH, Liu KM (2008) Age growth and reproduction of silky shark, Carcharhinus falciformis, in northeastern Taiwan waters. Fisheries Research 90: 78–85.
Konan KJ, Diaha NC, Sylla S, Amande MJ, Tapé GTJ (2014) Importance des requins dans les captures de la pêche artisanale aux filets maillants dérivants de Côte d’Ivoire. ICCAT Collective Volume Scientific Papers 70: 2446–2451.
Kouamé KYN, Konan KJ, Ouattara NI, Koné T (2019) Aspects of the reproductive biology of the blue shark Prionace glauca (Linnaeus, 1758) in the coastal waters of Ivory Coast, West Africa. Journal of the Marine Biological Association of the United Kingdom 99: 1435–1441.
Lana FO (2012) Ecologia do tubar~ao lombo-preto, Carcharhinus falciformis (Müller & Henle, 1939), na Margem Ocidental do Oceano Atlântico Equatorial (Master Thesis). Universidade Federal Rural de Pernambuco, Recife, Brasil.
Lezama-Ochoa N, Murua H, Ruiz J, Chavance P, De Molina AD, ... Sancristobal I (2018) Biodiversity and environmental characteristics of the bycatch assemblages from the tropical tuna purse seine fisheries in the eastern Atlantic Ocean. Marine Ecology 39(3): e12504.
Lombardi-Carlson LA, Cortés E, Parsons GR, Manire CA (2003) Latitudinal variation in life-history traits of bonnethead sharks, Sphyrna tiburo (Carcharhiniformes: Sphyrnidae) from the eastern Gulf of Mexico. Marine and Freshwater Research 54: 875–883.
Lopez J, Alvarez-Berastegui SD, Murua H (2020) Using fisheries data to model the oceanic habitats of juvenile silky shark (Carcharhinus falciformis) in the tropical eastern Atlantic Ocean. Biodiversity and Conservation 29: 2377–2397.
Morlière A, Rebert JP (1972) Hydrological study of the Ivorian continental shelf. Scientific documents from the Oceanographic Research Center, Abidjan 3(2): 1–30.
N’Goran YN, Amon-Kothias JB (2002) Biostatistical observations on sharks captured by the drift gillnet fishery in Côte d’Ivoire. Collective Volumes of Scientific Papers 54(4): 1421–1428.
N’Goran YN, Kouassi Y, Barrigah B (2005) Quantités et tailles des requins capturés par la pêcherie de filet maillant dérivant en côte d’ivoire, ICCAT Collective Volume of Scientific Papers 58(3): 1087–1095.
Oshitani S, Nakano S, Tanaka S (2003) Age and growth of the silky shark Carcharhinus falciformis from the Paciﬁc Ocean. Fisheries Science 69: 456–464.
Pratt HL (1979) Reproduction in the blue shark Prionce glauca. Fishery Bulletin 77: 445–470.
Rigby CL, Sherman CS, Chin A, Simpfendorfer C (2017) Carcharhinus falciformis. The IUCN Red List of Threatened Species 2017: e.T39370A117721799.
Ronquillo-Benıtez K (1999) Fisheries and biology of silky shark Carcharhinus falciformis (Bibron, 1839) in the Gulf of Tehuantepec, Chiapas, Mexico. Business Social Compliance Initiative (Bsci). Thesis, Universidad Nacional Auto´- noma de Mexico, Facultad de Ciencias, Mexico. 90 pp.
Stehmann MFW (2002) Proposal of a maturity stages scale for oviparous and viviparous cartilaginous fishes (Pisces, Chondrichthyes). Archive of Fishery and Marine Research 50(1): 23–48.
Tavares R (2009) Fishery biology of the Caribbean reef shark, Carcharhinus perezi (Poey, 1876), in a Caribbean insular plateform: Los Roqies Archipelago National Park, Venezuela. Journal Aquatic Science 4(4): 500–512.
Copyright (c) 2023 Journal of Fisheries
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.