A new species of Acusicola Cressey (Copepoda: Ergasilidae) from northeastern Brazil

Abstract

A new species of Acusicola is described based on adults of both sexes taken from plankton samples collected in the upper reaches of the Piauí River estuary, in the northeast of Brazil. Ovigerous females were present in the plankton. The new species, Acusicola minuta n. sp., can be distinguished from its congeners by its small body size, female antennal morphology and leg setation. The male described here as A. minuta n. sp. is the first known male attributed to the genus.

Gauchergasilus euripedesi (Copepoda, Ergasilidae) parasitizing different species of fish from two environments in southern Brazil

“…The ergasilid copepods are described mainly based on their morphology including shape and number of segments in each appendage, segmental setation, in addition to the patterns of spines and setae (Montú 1980;Araujo and Boxshall 2001;Montú and Boxshall 2002). The specimens of G. euripedesi found in this study presented all of the traits described by Montú (1980) and Montú and Boxshall (2002) as well as presented the measurements similar to those specimens reported by the two studies.…”

“…Until now, previous reports of fish parasitized by G. euripedesi include larvae of B. pectinata, Gobiesox sp., L. grossidens, and M. furnieri (Montú 1980), and adult specimens of G. brasiliensis and M. furnieri (Velloso and Pereira Jr. 2010;Rassier et al 2015). In additional reports, the specimens of G. euripedesi were collected from plankton samples, since only females are known to be parasitic (Araujo and Boxshall 2001;Montú and Boxshall 2002). This is the first report of G. euripedesi parasitizing species of Astyanax (A. lacustris) and Psalidodon (P. eigenmanniorum and P. aff.…”

“…This study also extends the known geographic record of G. euripedesi in the lagunar system of Patos Lagoon to the Jacuí Delta, and includes a new locality record (Itapeva Lagoon). It is possible that G. euripedesi could be found in other localities throughout the territory between southern and northeast Brazil since its distribution is only known in the states of Rio Grande do Sul and Sergipe (Araujo and Boxshall 2001;Montú and Boxshall 2002).…”

“…In addition, females of G. euripedesi were found in M. furnieri by Velloso and Pereira Jr. (2010) in the pre-limnic region of the Patos Lagoon estuary, and in Geophagus brasiliensis (Quoy & Gaimard, 1824) by Rassier et al (2015) also in the estuarine area of Patos Lagoon. Araujo and Boxshall (2001) reported G. euripedesi obtained from plankton samples collected in the Piauí River estuary. Currently the genus Gauchergasilus is monotypic (Montú and Boxshall 2002;Luque et al 2013).…”

Two new species of Acusicola Cressey, 1970 (Copepoda:Cyclopoida: Ergasilidae) parasitic on the gills of two estuarine actinopterygians off Brazil

“…The new species differs from all congeners by its possession of a maxillule armed with four elements (i.e., three regular setae and one spiniform element), since the maxillule of the other known species has two (as in A. cunula Cressey, 1970, A. lycengraulidis Thatcher & Boeger, 1983a , 1983b , A. paracunula Amado & Rocha, 1996 , A. pellonidis Thatcher & Boeger, 1983a , 1983b , A. rogeri Amado & Rocha, 1996 , A. rotunda Amado & Rocha C.E.F., 1996, A. spinulosa Amado & Rocha C.E.F., 1996, A. tenax (Roberts, 1965 ) and A. tucunarense Thatcher, 1984) or three elements (as in A. braziliensis Amado & Rocha C.E.F., 1996 , A. joturicola El-Rashidy & Boxshall, 1999 , A. margulisae Santacruz, Morales-Serna, Leal-Cardín, Barluenga & de León, 2020, A. mazatlanensis El-Rashidy & Boxshall, 1999 , A. minuta Araújo & Boxshall, 2001 , A. spinuloderma El-Rashidy & Boxshall, 1999 ) (Cressey & Collette, 1970 ; Thatcher & Boeger, 1983a ; Thatcher & Boeger, 1983b ; Thatcher, 1984; Amado & Rocha, 1996 ; El-Rashidy & Boxshall, 1999 ; Araújo & Boxshall, 2001 ; Santacruz et al 2020 ). Acusicola iamarinoi n. sp.…”