Cymothoa excisa Perty, 1833

Ribeiro, Felipe Bezerra, Huber, Augusto Frederico & Araujo, Paula Beatriz, 2021, Redescription of the fish-parasitic isopod Cymothoa ianuarii Schioedte & Meinert, 1884 and further records of C. excisa Perty, 1833 and C. oestrum (Linnaeus, 1758) (Isopoda: Cymothoida: Cymothoidae) from Brazil, Papéis Avulsos de Zoologia 61, pp. 1-10 : 2

Cymothoa excisa Perty, 1833

( Figs. 1 , 6 ; Table 1)

Restricted synonymy: Cymothoa excisa Perty,1833: 211 , tab. 40, fig. 11. Coelho & Koenig, 1972: 1976, table 1. Trilles 1994: 141. Thatcher et al., 2003: 545, figs. 27-51. Luque et al., 2013: 1454.

Material examined: BRAZIL: Bahia: one ovigerous female, Candeias, coll. J. Pezzi da Silva , 11/V/2010 ( MCP 2996 ) ; two ovigerous females, Candeias, coll. J. Pezzi da Silva , 11/V/2010 ( MCP 2997 ) [illustrated] .

Remarks: Cymothoa excisa was most recently diagnosed by Thatcher et al. (2003). The species had already been recorded from northeastern Brazil, in the states of Maranhão, Pernambuco and Sergipe by Coelho & Koenig (1972). These authors also raised the possibility of the occurrence in the states of Piauí, Ceará, Rio Grande do Norte, Paraíba, Alagoas, Bahia and Espírito Santo, the latter in the southeastern Brazil. In addition, the occurrence of this species was also recorded in the states of Pará ( Monod,1969) and Rio de Janeiro ( Richardson,1901).This is the first record for the state of Bahia, particularly in the northern portion (12°44′49″S 38°29′38″W). The southernmost record of C. excisa in western South Atlantic is La Plata ( Argentina) ( Gerstaecker, 1901). Cymothoa excisa was redescribed by Thatcher et al. (2003) based on material from the Florianopolis Island, state of Santa Catarina, southern Brazil. Females are distinguished mainly by the acute anterolateral angles of pereonite 1 reaching or surpassing the eyes; the truncate cephalon, deeply immersed in pereonite 1; eyes present but inconspicuous; pereonites 4-6 subequal in width; pleon deeply immersed in pereonite 7 ( Fig. 1 ); and pleopods trilaminate ( Thatcher et al., 2003). Males are similar to females, but smaller and with pleopod 2 lacking an appendix masculinum ( Thatcher et al., 2003).

Hosts: Thehostofpresentspecimensisunknown.However, C. excisa was already found parasitizing fishes of the families Gerreidae , Haemulidae , Lutjanidae , Priacanthidae , Sciaenidae and Synodontidae ( Joca et al., 2015) .

Distribution: USA (Massachusetts to Florida), Antilles, Venezuela, Brazil (Pará, Maranhão, Pernambuco, Bahia, Sergipe, Rio de Janeiro and Santa Catarina)and Argentina ( Trilles, 1994; Thatcher et al., 2003) ( Fig. 6 ).

Figures

Figure 1. Cymothoa excisa Perty,1833 (MCP 2996):(A) habitus dorsal view;(B) habitus ventral view; (C) habitus lateral view; (D) cephalon frontal view. Scale bar: A-C = 5 mm; D = 2.5 mm.

Figure 6. Map with the records of Cymothoa excisa (▲), C. ianuarii (⬛) and C.oestrum (⬤) in Brazil.Symbols in dark gray indicate literature records and white indicatesnewrecords.Abbreviations:PA =Pará;MA = Maranhão;PE= Pernambuco;SE = Sergipe;BA = Bahia;RJ = Rio de Janeiro;SP = São Paulo; SC = Santa Catarina.