Parathelges foliatus Markham, 1972b

Ribeiro, Felipe Bezerra, Campos-Filho, Ivanklin Soares & Bezerra, Luís Ernesto Arruda, 2019, New records of two species of parasitic isopods (Isopoda: Cymothoida: Bopyridae: Athelginae) associated with hermit crabs from the south Atlantic, Papéis Avulsos de Zoologia 59, pp. 1-7 : 2

Parathelges foliatus Markham, 1972b ( Figs. 1 , 4 )

Parathelges foliatus Markham, 1972b: 73 , figs. 14, 15. Markham, 2003: 74.

Material examined: BRAZIL: Ceará: one female, Camocim, Estuário do Rio Coreaú (02°53’42”S, 40°51’31”W), coll. F.B. Ribeiro, 13/X/2008, identified by D. Roccatagliata and F.B. Ribeiro, 13/X/2008, ( UFRGS 5970 ), infesting pleon of an ovigerous female of Clibanarius symmetricus (Randall, 1840) (5 mm CL; UFC 230 ) .

Diagnosis: Female: cephalon spade-shaped in outline, eyes absent, barbula with three sharp projections on each side, pereopods all alike and with prominent coxal segments, pleon with distinct segments, exopodites of pleopods long and rounded at ends, pleotelson not set off. Males are unknown.

Remarks: Parathelges foliatus was described based on a female (TL 8.33 mm) from Trinidad, being reported only from the type-locality ( Markham, 1972b). The specimen examined here is morphologically similar to the material described by Markham (1972b), showing the pereon with all segments well distinguished dorsally, marsupium closed ventrally,pleopodal exopodites on peduncles and with distal margins rounded ( Fig. 1A, B ). Additional morphological characters not mentioned in previous descriptions include: antennule with three articles and antenna with four articles ( Fig. 1C, D ), and pereopod 7 with dactylus embedded in the propodus ( Fig. 1I ). This is the first record of this species from Brazilian waters and second for the western Atlantic Ocean. In addition, this is the third genus of Athelginae recorded from Brazil; the genera Anathelges Bonnier, 1900 from the state of Santa Catarina and Pseudostegias are known from the states of Ceará and Alagoas, respectively ( Brasil Lima, 1998).

Representatives of the genus Parathelges infest diogenid hermit crabs of the genera Allodardanus Haig & Provenzano, 1965 , Calcinus Dana, 1851 , Clibanarius Dana, 1852 and Dardanus Paul’son, 1875 ( Markham, 2003). Parathelges foliatus was described infesting the same host of our specimen, the hermit crab Clibanarus vittatus (Bosc, 1802) . However, Negri et al. (2014) established that populations of C. vittatus should be restricted to the southeastern coast of the United States and Gulf of Mexico. Specimens from the Caribbean to southern Brazil should be classified as Clibanarius symmetricus (Randall, 1840) , which is therefore the identity of the host of P. foliatus . According to Markham (1972b), species of Parathelges are usually found associated with shallow-water hosts, which agrees with our specimen collected attached to a hermit crab in the intertidal zone of an estuarine area.

Distribution: Western Atlantic: Trinidad and Brazil (state of Ceará) ( Fig. 4 ).

Figures

Figure 1. Parathelges foliatus Markham, 1972 (UFRGS 5970): (A) habitus dorsal view; (B) habitus ventral view;(C) antennula; (D) antenna; (E) barbula; (F) maxilliped;(G) oostegite 1; (H) pereopod 1; (I) pereopod 7.Scale bars:Aand B = 5 mm;C = 0.1 mm;D and G = 0.5mm; E = 0.1 mm;F,K and L = 1.00 mm; H = 0.3 mm; I = 1.5 mm.

Figure 4. Distribution map of parasites (Parathelges foliatus and Pseudostegias atlantica) (circles and squares) and associated hosts (hermit crabs) (stars).Black circles and squares represent previous records and white circles and squares newrecords for parasites.White and black stars represent the distribution ofClibanarius antillensisand C.symmetricusrespectively from Venezuela toBrazil accordingto Coelho et al.(2007),Negri et al.(2014),Nucci & Melo (2015) and Lemaitre & Tavares (2015).