A review of the ecological knowledge on the species <i>Batrachoides liberiensis</i> in estuarine and lagoon environments of West Africa

Scientific fishing programmes were carried out between 1979 and 2013 in several West African estuarine, coastal lagoon ecosystems. Batrachoides liberiensis represented only 5.2% of the occurrences, which majority recorded Sine Saloum estuary. This originality makes it possible to use this population characterise certain features biology ecology little described species. B. was waters with a salinity 25–46, transparency 1–3.5 m, at depths 2–10 m. It particularly abundant areas distance 15–35 km from mouth. The water temperature did not appear be determining factor for sex ratio population, whose total length ranged 10 371 mm, favour females (87%) an estimated size first maturity 189 mm (total length). parameters length-weight relationship K = 1.0009*10−5 b 3.097. diet consisted mainly molluscs crabs, present respectively, 53.6% 50.7% stomach contents analysed. Des de pêche scientifique ont été réalisés entre et dans plusieurs écosystèmes estuariens, côtiers lagunaires d'Afrique l'Ouest. ne représentait que 5,2 % des cas, dont la majorité enregistrée l'estuaire du Saloum. Cette singularité permet d'utiliser cette pour caractériser certains traits biologie l'écologie espèce peu décrite. enregistré eaux ayant une salinité comprise 25 46, transparence allant 1 à 3,5 profondeurs 2 était particulièrement abondante les zones situées 15 35 l'embouchure. La température l'eau semblait pas être un facteur déterminant espèce. répartition par sexe longueur totale allait en faveur femelles (87 %) avec taille estimée première maturité (longueur totale). Les paramètres relation longueur--poids estimés 1,0009*10−5 3,097. Le régime alimentaire se compose principalement mollusques crabes, présents respectivement 53,6 50,7 contenus stomacaux analysés. Estuarine environments are original ecosystems that part both marine continental realms. These commonly inhabited by species, freshwater species endemic these environments. In absence anthropogenic interventions (pollution, development, resource exploitation, etc.), biomass produced estuarine is exceptionally high (Elliott al., 2007). origin numerous food chains (Potter 2015). They also irreplaceable breeding feeding ground many (Martinho 2007; Vidy, 2000). Since 1980s, research projects have focused on fish populations coastal, Africa (Figure 1) as well their hydro-climatic environment. Studies been conducted Ebrié Lagoon Côte d'Ivoire (Albaret, 1994), Fatala Dangara estuaries Guinea (Baran, 1995), Gambia estuary (Albaret 2004; Simier 2006; Vidy 2004), complex Senegal (Diouf, 1996; Ecoutin 2010; 2013; 2014; Sadio 2015; 2000), Bijagos Islands Rio Buba Bissau (Deme-Gningue 1994; Diouf Sadio, 2015) zone Banc d'Arguin National Park Mauritania (Sadio, All resulting data incorporated information system entitled “Fish communities artisanal fisheries ecosystems” (French acronym PPEAO) (http://ppeao.ird.fr – 2019a). made conduct syntheses or groups including Mugilidae & Legendre, 1985), Gerreidae Desfossez, 1988), shortfin pompano Trachinotus teraia (Trebaol, 1991), bongo shad Ethmalosa fimbriata (Charles-Dominique Albaret, 2003), bobo croaker Pseudotolithus elongatus (Carassou, 2003) Ariidae (Simier 2021). aim work deepen our knowledge distribution hairy toadfish (Steindachner, 1867), usually sea, but making extensive environment, yet very scarce. First, we assess presence six Mauritania. Secondly, focus its spatial preferences terms mouth environmental salinity, temperature, depth. Finally, structure, length–weight relationship, reproduction trophic behaviour provide better understanding poorly known belongs order Batrachoidiformes family Batrachoididae. According Collette Russo (1981), demersal lives tropical off Atlantic coast northern Angola (14° N–17° S). inhabits marine, brackish waters. Although throughout region (Froese Pauly, 2021), great ecological economic importance. target fisheries, partly because low abundance rather small size, being maximum 46 cm (Schneider, 1990). Batrachoididae, genus found eastern Atlantic, other eight western Pacific, either side Isthmus Panama (Collette Russo, 1981; Greenfield 2008). For reason, considered (1981) representative primitive condition Batrachoides. often common name toadfish. vernacular terminology, has identified. used collected researchers IRD (Institut Français Recherche le Développement) during experimental surveys different assemblages countries 1). sampling protocols implemented documents accessible PPEAO 2019b). Whatever protocol, each operation documented station (geographical coordinates, depth mouth) physico-chemical environment (water transparency). Only operations using fyke nets 1995 1997 include measurements. methodology collecting always same. captured identified level. Almost all individuals measured nearest millimetre length) when collected, some weighed gram. Often, determined stage evaluated according scale established Albaret Legendre (1985). Information provided individuals. Statistical analyses graphs R software (R Core Team, Linear regressions log(W) vs. log(TL), where W weight g TL calculated obtain form K*TLb (Froese, 2006) log(K) intercept slope log–log regression. Individuals outliers step involving removed before second regression improve quality fit. 50% mature TL50) could done logistic after grouping into classes calculating percentage class. scientist charge collection manipulation holds “University Diploma Animal Experimentation, Level II Accreditation n° I-51UFRReims-S2-09 University Reims Champagne-Ardennes” “Animal Experimentation School Design implementation procedures Laboratory Physiopathology Functional Pharmacology ONIRIS Ecole Nationale Vétérinaire, Agroalimentaire l'Alimentation Nantes Atlantique,” ensures animal welfare respected faunal surveys. No harsh practices chemicals immobilise kill handling. Measurement, weighing observation gonads dead. specimens processed alive. A 261 caught system. 184 operations, is, 310 collected. view 3514 more than 217,000 2019a), seems clear well-represented environments, regardless selectivity problems gear used. four studied: Senegal, Gambia, islands archipelago inlet (Table (Mauritania) nor (Côte d'Ivoire) despite large number latter ecosystem fact, really (Senegal) 9.1% operations. Small numbers (1.8% operations) occasionally (1% present, 11 recorded, one two 86.4% (one individual 69.6% 16.8%). estuary, 90% occurrences Farther less mouth, rarely recorded. proportion trips 5 up 60 confirmed homogeneous (Chi-squared 48.096, p 3.008. 10−6): 17.7% 20 km, 8.3% 12.3% 30 14.2% while exceed 6% 0 km. few times beyond 50 moderate puts perspective. Its impossible analyse variable. minimum, mean values bottom listed Table 2, together range containing observations Low (<1 m) (4/4 observations) (7/8). (<22) (2/4) (4/8). archived system, exception preferential (90%) limited. structure (TL) (mean 200.3 ± 53.4 mm). unimodal mode 198 2). Half 167 234 mm. Bissau, small, 120 (mm) (g) 218 male female individuals, measuring 328 630 g, 3.097 (± 0.0297) correlation coefficient r 0.99. 131 covering entire (84–328 mm) Among 31 (≤230 determined. differentiated, (SR) favourable (87% females, SR 6.7 male). 45% maturing mature. smallest beginning sexual maturation 140 spawning spent stage. 87 305 34 mature, 22.1 Occasional reports indicate eggs 5–6 diameter. sexually January August, represents dry season includes rainy season. 69 (measuring 286 examined sampling. 87.3% comprised category. all, categories recorded: (53.6% observations), bivalves (29%), crabs (50.7%) fish, echinoderms various plant debris. results confirm sparse already liberiensis. With indeed rare since seldom occur. (TL). Udo al. (2017) landings distant boats Ibeno, Qua Iboe River (Nigeria), 130 2015, however, same authors reported 233 Ibeno Town, vessels South-eastern Nigeria (Udo Udoh, 245 given (2016) FAO identification guide living resources Eastern Central Atlantic. Field Guide commercial Gulf Guinea, Schneider (1990) reach 460 Therefore, except Schneider's estimation, largest coast. sample (W TL3.097, 0.99), body differs 8 13 cm, (Nigeria): 0.0582 TL2.3327 (r 0.8466), expressed cm. weights 15.7 12.5 respectively. Our covers wider larger no 122 (SL, estimate 145 TL) Ghana study primarily carcinophagous malacophagous, secondarily piscivorous. generally benthophagous, consume zoobenthos, crustaceans 1981), (Collette, 2016), shrimps 1996). Nigeria, Udoh (2015) noted dominance followed crustaceans. confirms predatory liberiensis, generalist tendency, consumption apparently favoured Albaret's (1999) classification, category accessory relatively reproducing areas, there limited time and/or space. Whitfield's (2005) migrant, breeds juveniles adults show varying degrees dependence nursery areas. Little liberiensis; articles describing report presence. Africa, occasions 10.5 Gushchin Fall, 2012), artificial reef Yenne, village Terashima 2007), River, Tanbi Wetland Park, 0.1% 0.2% abundances (Ceesay 2016). inventory catalogues, example, Sierra Leone (Kamara, 1977) (Ofori-Adu, 1988) papers taxonomy Fisher Scialabba, 1988; Roux, On shelves adjacent studied, scarcity Senegalese-Gambian shelf almost never scientific trawl 1970 s 1980 (Caverivière Domain, 1980). (Domain, 1989), (Domain 1999), (Caverivière, 1993; Troadec 1969) Togo (Lhomme, 1984). higher indicated river through (2017). When explaining why ovaries shelf, suggested differences explained therefore supply conditions ecosystem. revealed should highlighted. What particularities allow flourish there? preferred Beyond fluvial can increase tolerance (around 55) limits extension upstream. directly linked stable plentiful resources. would line hypothesis put forward However, due available lack nearby remains hypothesis. financial support Research Projects (Mauritania, Guinea-Bissau, d'Ivoire). thank everyone indirectly involved surveys, collection, especially fishermen crew vessels. Without help, declare conflicts interest. freely request www.ppeao.ird.fr.