ISSN 1809-127X (online edition) © 2010 Check List and Authors Chec List Open Access | Freely available at www.checklist.org.br Journal of species lists and distribution PECIES S two tropical estuaries of Bahia, Brazil OF Mesozooplankton 1*, Bárbara and Luciana Ichthyoplankton da Conceição 1 composition 2, Paulo in ISTS 2 1 L and Rodrigo Johnsson Catarina da Rocha Marcolin , Marcos Moura Nogueira Mafalda Júnior Associada). CEP 40170-110 .Salvador, BA, Brazil. 1 Universidade Federal da Bahia, Campus de Ondina, Instituto de Biologia, Departamento de Zoologia, LABIMAR (Crustacea, Cnidaria e Fauna Salvador, BA, Brazil. * 2 CorrUniversidadeesponding Federal author. da E-mail: Bahia, [email protected] Campus de Ondina, Instituto de Biologia, Departamento de Zoologia, Laboratório de Plâncton. CEP 40170-110. Abstract: The objective of this study was to describe the composition of two mesozooplankton and ichthyoplankton estuarine communities in Jandaíra, Bahia (Tabatinga River), impacted by a shrimp farm; and in Conde, Bahia (Itapicuru River), a pristine estuary. Samples were collected through horizontal hauls using a net (200 µm mesh size), coupled to a 76 and 92 taxa were registered. The most abundant groups were Pseudodiaptomus richardii and Disco sp. Acartia lilljeborgi flowmeter,was also dominant during the at ebbingTabatinga, and floodingwhile Temora tides insp. April, and Augustdecapod and larvae December, were predominant 2007. In the Tabatingain Itapicuru and River, Itapicuru which Rivers also distribution and new geographical records of Disco sp., P. richardi, Pontellopsis villosa, Macrosetella gracilis, Microsetella roseapresented, Gonyiopsillus higher densities brasiliensis for most, Agetus planktonic flaccus and taxa, Ergasilus particularly caraguatatubensis fish larvae. A descriptive were presented. analysis of the main taxa´s spatial Introduction shrimp farms in the state of Bahia, which was implemented The estuaries and mangroves are currently one of the world’s most threatened ecosystems due to h treatment in sedimentation ponds. drastic encroachment of human activities despite their in 1993.In the The Itapicuru discharge River’sof effluents basin, occurs other daily, sources after a 24of undeniable relevance (Barbier and Cox 2002; Singkran anthropogenic impacts can be found in the main course and Sudara 2005). According to Islam and Haque (2004), shrimp farming has been a great contributor to mangrove However, close to the mouth of the Itapicuru River there is a destruction, reducing biological resources such as habitats smallof the villageriver, such where as sewageno industrial and industrial activities effluentswere observed. waste. economic relevance. economic activities, but both are still poorly developed. of crustaceans,Zooplankton mollusks plays a key and role fish in species the ecosystem of ecological structure and TourismIn both and rivers, artisanal four samplingfishery are stations the mostwere importantchosen to due to its quick response to abiotic conditions, especially in collect data according to the decreasing salinity gradient impacted environments (Levinton 1995; Neumann-Leitão (Figure 1). et al. 1999). It is, therefore, very important to describe the taxonomic diversity in tropical estuaries since there is no Data collection published information on the composition of zooplankton The sampling strategy was carried out in four stations communities in the state of Bahia, only some unpublished academic works which focused mainly on ecological tides. This data was collected in the rainy (April and aspects. in each estuary during the ebbing and flooding spring This paper presents a description of the zooplankton 2007, consisting of 48 samples. Salinity and temperature and ichthyoplankton taxa density found in two similar wereAugust estimated months) throughand dry a(December multi-parameter month) probe seasons WTW of tropical estuaries subjected to different sources of 340i/SET. anthropogenic impact in the state of Bahia. It also highlights new records of some copepod species distribution. horizontal hauls at 0.1 m from the surface, during 3 minutes,Mesozooplankton using a conical samples net (200 wereµm mesh collected size) coupled through to Material and Methods Study site samples were preserved in 4 % formaldehyde seawater The Tabatinga River estuary is part of the Real solutiona flowmeter and transportedfor filtered volumeto the laboratory. determination. Plankton River Basin located in the city of Jandaíra (11°32’45” S, 037°29’19” W) and the Itapicuru River estuary is part lowest practical taxonomic level through an estereoscopic of the Itapicuru River Basin located in the city of Conde Organisms were counted and identified to their (11°47’38” S, 037°30’53” W), in the farthest north littoral CH30) and the pertinent bibliography (Smith 1982; in the state of Bahia, Brazil. They are under like climate Boxshallmicroscope and (Leica Halsey MZ6), 2004; an opticalBoltovskoy microscope 2005; (OlympusRichards regimes, varying from humid to sub-humid. 2006). The abundance of organisms was estimated The Tabatinga River is adjacent to one of the largest through measuring 2, 10 or 50 mL aliquots, one aliquot per Check List | Volume 6 | Issue 2 | 2010 210 Marcolin et al. | Mesozooplankton and Ichthyoplankton composition in two tropical estuaries of Bahia, Brazil sample, using a Stempel pipette. Rare taxa were counted in Considering both zooplankton and ichthyoplankton a total of 76 and 92 taxa were recorded in the Tabatinga and meter) was calculated dividing the abundance by the total Itapicuru Rivers, and they are displayed on tables 1 to 4 the whole sample and the density (D: individual per cubic with their respective density data. A total of 98 mesozoo- The specimens referred to in this work are deposited and 20 ichthyoplankton taxa were recorded taking into filtered volume. account both rivers. (UFBA). at the Museu de Zoologia / Universidade Federal da Bahia Disco sp. ThereThe are most no previous relevant recordsfinding forrefers Disco to in the the first Southwestern register of DiscoidaeAtlantic, nor (Copepoda, in estuaries, Calanoida), being typically represented considered by as an oceanic group (Boxshall and Halsey 2004). Currently the family is divided into three genera containing 29 species. However only two of them belong to Prodisco and four to Paradisco, the other 23 species are attributed to the genus Disco. Schulz (1993) proposed a subdivision of the Disco species according to the degree of mouth parts reduction. The specimens found in these estuaries represent a new species which is being described by the authors. copepod species in the state of Bahia: Pseudodiaptomus richardiThis study also representsPontellopsis the firstvillosa record Brady, of other 1883, 7 Macrosetella gracilis Microsetella rosea 1847, Gonyiopsillus Dahl, 1894, brasiliensis 2000, Agetus flaccusDana, Giesbrecht, 1847, 1891 and Ergasilus Dana, caraguatatubensis Amado and Rocha, Huys 1995.and Conroy-Dalton, Figure 1. Sampling stations’ disposition in the Tabatinga River estuary (1 to 4) surrounding a shrimp farm and in the Itapicuru River estuary (1 to 4). RR: Real River; TR: Tabatinga River; IR: Itapicuru River; P: ponds; I1-I4: stations 1 to 4 at Itapicuru River; T1-T4: stations 1 to 4 at Tabatinga River. Figure 2. Results And Discussion The temperature was similar at all the sampling T-S Diagram at Tabatinga River during April, August and December, ebbing and flooding tides. stations with smaller values in August. The salinity was a very variable parameter, which represented a decreasing gradient from station 1 to 4 in both estuaries (Tabatinga River: 5.90 to 26.30; Itapicuru River: 8.60 to 36.30). The season. The T-S diagram shows the existence of only estuarinehigher values waters were in thefound Tabatinga in December River (Figure during 2), the while dry estuarine and coastal waters were present in the Itapicuru River (Figure 3). In the Tabatinga and Itapicuru Rivers, 65 and 73 zooplankton taxa were registered, respectively; 59 of them were found in both estuaries such as Foraminiferida, Urochordata, Cephalochordata and Chaetognatha. Rotifera wasCnidaria, solely Annelida, recorded inMollusca, the Tabatinga Echinodermata, River while Crustacea, Thaliacea larvae, 11 and 19 species were found on these estuaries. Figure 3. was only registered in the Itapicuru River. In relation to fish T-S Diagram at Itapicuru River during April, August and December, ebbing and flooding tides. Check List | Volume 6 | Issue 2 | 2010 211 Marcolin et al. | Mesozooplankton and Ichthyoplankton composition in two tropical estuaries of Bahia, Brazil Ergasilidae is one of the most important families Crustacean’s predominance was striking for both Ergasilus estuaries where the highest density and dominance (%) caraguatatubensis (Tables 2 and 3) were recorded especially for calanoid andof copepodsRocha (1995) which inhabiting are fish the parasites.opercular cavity of copepods (Pseudodiaptomus richardi Disco was first described by Amado sp., Temora sp. and Acartia lilljeborgi) and decapod São Paulo and Rio de Janeiro. Therefore the occurrence larvae (Ucides cordatus Linnaeus, 1763).Dahl, This 1894, trend was ofMugilidae E. caraguatatubensis collected in the and states Mugil of Maranhão,liza Valenciennes, Alagoas, congruent with most studies carried out in estuarine and coastal zooplanktonic communities (Fonseca and restricted to the Itapicuru River. Klein 1976; Vega-Pérez 1993; Gaughan and Potter 1995; 1836Caligus (Mugilidae) may be