Gobioides broussonnetii Lacepède, 1800 (Pisces: Gobiidae): First record of the violet goby in the state of Bahia (central coast of Brazil) and evidence of the effect of increased salinity on its local distribution

The violet goby, Gobioides broussonnetti is a large member of the Gobiidae family and its estimated distribution extends from the Atlantic coast of the United States to Paraná, Brazil, including the Gulf of Mexico and the Caribbean coasts of Colombia, Venezuela and French Guyana (Hoese and Moore 1998; Murdy 1998; Passos et al. 2012). It typically occurs in marine and estuarine environments (Hoese and Moore 1998; Camargo and Isaac 2003) but has been found in fresh water (Rodríguez and Villamizar 2006). It prefers muddy sediments where it is commonly captured (Cervigón 1994) and reaches 60 cm in total length, making it the largest species of its family to occur in the western Atlantic (Menezes and Figueiredo 1985). Little data is available on the ecology and life history of this species, with the exception of some systematic (Pezold 1993; Murdy 1998) and a few recent studies on its economic importance to traditional fisheries (Bragança 2005, unpublished data) and its feeding ecology and reproduction (Mata-Cortés et al. 2003; Rodríguez and Villamizar 2006). To the best of our knowledge, records of this species in Brazilian waters to date have been reported in the Amazon (Camargo and Isaac 2003) and Caeté River estuaries (Barletta et al. 2005) in northern Brazil, on the coast of Ceará in northeastern Brazil (Araújo et al. 2000), in the São Mateus river estuary (Sarmento-Soares and Martins-Pinheiro 2012) and the Cananéia estuarine complex (Menezes and Figueiredo 1985) in southeastern Brazil, and in the Itajaí-Açu river estuary (Antunes 2010, unpublished data) and the Antonina Bay (Cortelete et al. 2009) in southern Brazil. In all of the above-listed reports, G. broussonnetii showed low abundance and was always captured in the mixohaline zones of estuaries. According to Andrade-Tubino et al. (2008), who synthesized studies Abstract: New recordings of Gobioides broussonnetii Lacepède, 1800 and the distribution of which extends for approximately 1,000 km both to the North and South along the coast of Brazil are reported in the Paraguaçu river estuary (Todos os Santos Bay). Preliminary data regarding the impact of increasing salinity on violet goby populations are shown and discussed. 1 Universidade Federal da Bahia – UFBA, Instituto de Biologia, Laboratório de Ecologia Bentônica and PPG em Ecologia e Biomonitoramento, Rua Barão de Jeremoabo, Ondina. CEP 40170115. Salvador, BA, Brazil. 2 ECUS, Instituto de Educação, Ciência e Utilidade Sócio-Ambiental, Rio Vermelho. CEP 41940-250. Salvador, BA, Brazil. * Corresponding author. E-mail: amorim_agua@yahoo.com.br José Amorim Reis-Filho 1,2,* and Heigon Henrique Queiroz Oliveira 2 Gobioides broussonnetii Lacepède, 1800 (Pisces: Gobiidae): First record of the violet goby in the state of Bahia (central coast of Brazil) and evidence of the effect of increased salinity on its local distribution

The violet goby, Gobioides broussonnetti is a large member of the Gobiidae family and its estimated distribution extends from the Atlantic coast of the United States to Paraná, Brazil, including the Gulf of Mexico and the Caribbean coasts of Colombia, Venezuela and French Guyana (Hoese and Moore 1998;Murdy 1998;Passos et al. 2012).It typically occurs in marine and estuarine environments (Hoese and Moore 1998;Camargo and Isaac 2003) but has been found in fresh water (Rodríguez and Villamizar 2006).It prefers muddy sediments where it is commonly captured (Cervigón 1994) and reaches 60 cm in total length, making it the largest species of its family to occur in the western Atlantic (Menezes and Figueiredo 1985).Little data is available on the ecology and life history of this species, with the exception of some systematic (Pezold 1993;Murdy 1998) and a few recent studies on its economic importance to traditional fisheries (Bragança 2005, unpublished data) and its feeding ecology and reproduction (Mata-Cortés et al. 2003;Rodríguez and Villamizar 2006).
To the best of our knowledge, records of this species in Brazilian waters to date have been reported in the Amazon (Camargo and Isaac 2003) and Caeté River estuaries (Barletta et al. 2005) in northern Brazil, on the coast of Ceará in northeastern Brazil (Araújo et al. 2000), in the São Mateus river estuary (Sarmento-Soares and Martins-Pinheiro 2012) and the Cananéia estuarine complex (Menezes and Figueiredo 1985) in southeastern Brazil, and in the Itajaí-Açu river estuary (Antunes 2010, unpublished data) and the Antonina Bay (Cortelete et al. 2009) in southern Brazil.In all of the above-listed reports, G. broussonnetii showed low abundance and was always captured in the mixohaline zones of estuaries.According to Andrade-Tubino et al. (2008), who synthesized studies Abstract: New recordings of Gobioides broussonnetii Lacepède, 1800 and the distribution of which extends for approximately 1,000 km both to the North and South along the coast of Brazil are reported in the Paraguaçu river estuary (Todos os Santos Bay).Preliminary data regarding the impact of increasing salinity on violet goby populations are shown and discussed.
José Amorim Reis-Filho1,2,* and Heigon Henrique Queiroz Oliveira 2 Gobioides broussonnetii Lacepède, 1800 (Pisces: Gobiidae): First record of the violet goby in the state of Bahia (central coast of Brazil) and evidence of the effect of increased salinity on its local distribution of the temporal-spatial organization of estuarine fish fauna along the coast of Brazil, G. broussonnetii is absent from the East coast of Brazil in at least some of those studies.Hatje and Andrade (2009) and Sousa et al. (2001) published studies on the Todos os Santos Bay in the state of Bahia, which do not report the species, despite the latter focusing specifically on the Gobiidae family.Recent studies of the Paraguaçu estuary (Reis-Filho et al. 2010;2011;2012) do not mention the violet goby either, because have been carried out mainly in shallow high salinity estuarine zones.
This study reports the recording of Gobioides broussonnetti (Figure 1) in the Paraguaçu river estuary (Figure 2), inside the Todos os Santos Bay (TSB) on the East coast of Brazil.Species identification was performed consulting the Menezes and Figueiredo (1985) which  present a taxonomic guide and general remarks about the species.The species of the Gobioides genus differ from other gobies by having long bodies and a first dorsal fin with one spine joined to a second dorsal fin.Among the genus Gobioides, G. broussonnetti differs from other species by having an oblique mouth, the anterior part of the lower jaw in a horizontal position with the eyes and body of a purplish-brown color (Murdy 1998).These recordings are one of the results of a long term fish and fisheries monitoring program carried out in the area.Bimonthly experimental sampling of fish and environmental variables such as salinity has been done in the area since January 2010.The collection of this type of data has made it possible to make inferences about the effect of salinity changes on the local distribution of the violet goby.We would like to thank the Eduardo Marocci, Bruno Menezes and Janilson "Águia" for their assistance in sample collection and all of the fishermen who participated in the Fishery Monitoring Program and the Federal University of Bahia (UFBA) by deposit of vouchers in its zoological collection.This study was funded by ECUS, Instituto de Educação, Ciência e Utilidade Sócio-Ambiental and ICHTUS soluções em meio ambiente LTDA.

Literature Cited
Andrade-Tubino, M.F., A.L.R. Ribeiro and M. Vianna. 2008 4 shows how the upstream flow control and consequent increase in salinity affects the occurrence of the violet goby is its population.Nowadays, violet goby individuals are captured only in regions of the Paraguaçu river where salinity still has little influence (see locations 1 and 2, Figure 2).Finally, based at the captures of Gobioides broussonnetti presented here we suggest that this species and its populations are suffering significant damage, both by alteration to habitat quality and overfishing, which is a result of the general scenario of local fishery activity.Even if the G. broussonnetii population recorded in the Paraguaçu estuary is well-established, the current conditions reported above may be a sign that the violet goby is threatened.Moreover, data collected on traditional fisheries might be inestimable information regarding estuarine biodiversity, especially rare and/or unusual fish species.We recommend more investigation into life cycles and responses to salinization of the upper estuary and principally an immediate return to past hydrological conditions which are more appropriate to the fitness of this species.Besides, the present type record becomes very useful for biogeographic knowledge mainly when is important relate environmental factors and biogeographic fingerprint and thereby have both played a role in structuring the components of Atlantic fish assemblages.

Figure 2 .
Figure 2. Area of distribution of Gobioides broussonnetii on the coast of Brazil.(a) The gray circles represent the recording along the coast of Brazil and black stars represent the new recordings in the Todos os Santos Bay; (b) black stars and theirs numbers represent the upper estuary (Paraguaçu river) where the violet goby was captured in recent years (2010-2013), dotted circles represent others areas in the Long Term Fish and Fisheries Monitoring Program and experimental sampling.

Figure 3 .
Figure 3. Environment and locations where Gobioides broussonnetii specimens were recorded.A) Main channel of the towns of São Felix and Cachoeira ; B) Tacha location with fishermen removing a trawl net from the edge of the main channel; C) Valéria location and typical riverside vegetation and D) the Nagé community with the Iguape bay visible in the background.

Figure 4 .
Figure 4. Number of Gobioides broussonnetii individuals captured in the upper estuary of the Paraguaçu river (Todos os Santos Bay, Bahia) along the mixohaline main channel over a four year period.Average bi-monthly salinity values are also shown as white circles.