Braga cigarra comb . nov . for Philostomella cigarra ( Crustacea : Isopoda : Cymothoidae ) with a redescription of the species based on specimens from Galeocharax kneri , a freshwater fish of Minas Gerais State , Brazil

Specimens of a cymothoid isopod from a freshwater fish of Minas Gerais State were studied. These were found to be morphologically comparable to Philostomella cigarra Szidat & Schubart, 1960, except for having multilaminate pleopods which is the distinguishing characteristic of the genus Braga Schiödte & Meinert, 1881. The first pleopod is bilaminate while the second is quadrilaminate. Pleopods three to five are trilaminate. It is herein proposed that the generic name Philostomella Szidat & Schubart, 1960, should be considered invalid and that the species P. cigarra should be transferred to Braga. Braga now contains eight species, including B. cigarra comb. nov., all from South American freshwater fishes. The principal difference between this species and the others in the genus is the form of the female which has a narrow pleon and a small pleotelson. A redescription of this species is presented here because previous descriptions in the literature are inaccurate or incomplete.


MATERIAL AND METHODS
Fish hosts, Galeocharax kneri (Steindachner, 1879), were netted in the Rio Grande, near Lavras, State of Minas Gerais, Brazil.They were taken on ice to the Department of Veterinary Medicine of the Universidade Federal de Lavras for examination.The isopod parasites were removed from the mouth of the hosts and fixed in 70% ethanol.The preserved specimens were sent to the Department of Zoology of the Universidade Federal do Paraná, Curitiba, for detailed studies.There, dissec-tions of the mouthparts, pereopods, pleopods and uropods were examined after clearing in pure phenol to better visualize their morphology.Photographs were made with a digital camera which were used in making the drawings.Measurements are given in micrometers (µm) except where designated as millimeters (mm).

TAXONOMY
Material examined.Six females and seven males collected by the second author from the mouth of Galeocharax kneri caught in the Rio Grande near Lavras, Minas Gerais State, Brazil.The females measured 18-27 (23) mm long by 8-12 (10) mm wide and the males 17-28 (23) mm long by 8-12 (10) mm wide.

DISCUSSION
SZIDAT & SCHUBART (1960) described a cymothoid isopod from the mouth of a characid fish from the Mogi-Guassu River, near Pirassununga, state of São Paulo, Brazil.They believed that this cymothoid represented a new genus and they gave it the name Philostomella cigarra.Their new genus was based mainly on the body shape of the female which has a narrow pleon and a small pleotelson.Apparently, they did not examine the pleopods.LEMOS DE CASTRO (1981) listed this species as a synonym of Braga cichlae Schiödte & Meinert, 1881, perhaps because the males resemble that species.TABERNER (1986) studied specimens from the same locality and from the same host fish, Galeocharax humeralis (Valenciennes, 1834).He reached the conclusion that Philostomella Szidat & Schubart, 1960 should be considered valid since it had multilaminate pleopods which were unknown in other genera.Apparently, he did not examine the pleopods of any species of Braga.THATCHER (1995) studied the pleopods of eleven species of parasitic isopods from Brazil and compared their morphol-ogy.The cymothoid genera examined were: Artystone Schiödte, 1886, Asotana Schiödte & Meinert, 1881, Braga, Nerocila Leach, 1818, Riggia Szidat, 1948and Telotha Schiödte & Meinert, 1884.In Braga, the following nominal species were examined: B. cichlae, B. nasuta and B. patagonica.It was found that all species of Braga had multilaminate pleopods and that these structures in the other genera were all bilaminate.In Braga spp., only the first pleopod is bilaminate while the second is quadrilaminate and the third to the fifth are all trilaminate.It was therefore concluded that multilaminate pleopods are the determining character of Braga.
In the case of Philostomella, TABERNER (1986) affirmed that multilaminate pleopods should define the genus.He stated that the first was bilaminate and all the others trilaminate.We find that specimens of P. cigarra have multilaminate pleopods exactly comparable to those of species of Braga, including a quadrilaminate second pleopod.Since the latter genus was proposed first, it takes precedence over Philostomella.The species cigarra can be separated from the others in the genus on the basis of the narrow pleon and small pleotelson of the female.The species should therefore be considered valid and transferred to Braga.
Braga cigarra comb.nov. is apparently quite host specific.It was originally found in a freshwater fish known locally as "peixe cadela" in Southern Brazil.The scientific name of the host at that time was Cynopotamus humeralis Valenciennes, 1834.The name of the host has since been changed to Galeocharax humeralis (Valenciennes, 1834).Our material came from a related species, Galeocharax kneri (Steindachner, 1879) from Minas Gerais State, Brazil.

Braga cigarra comb. nov. for Philostomella cigarra (Crustacea: Isopoda: Cymothoidae) with a redescription of the species based on specimens from Galeocharax kneri, a freshwater fish of Minas Gerais State, Brazil Vernon E. Thatcher 1 ; Antonio A. N. de Oliveira 2 & Adriana M. Garcia 2
ABSTRACT.Specimens of a cymothoid isopod from a freshwater fish of Minas Gerais State were studied.These were found to be morphologically comparable to Philostomella cigarraSzidat & Schubart, 1960, exceptfor having multilaminate pleopods which is the distinguishing characteristic of the genus Braga Schiödte & Meinert, 1881.The first pleopod is bilaminate while the second is quadrilaminate.Pleopods three to five are trilaminate.It is herein proposed that the generic name Philostomella Szidat & Schubart, 1960, should be considered invalid and that the species P. cigarra should be transferred to Braga.Braga now contains eight species, including B. cigarra comb.nov., all from South American freshwater fishes.The principal difference between this species and the others in the genus is the form of the female which has a narrow pleon and a small pleotelson.A redescription of this species is presented here because previous descriptions in the literature are inaccurate or incomplete.KEY WORDS.Cymothoid; freshwater fish parasite; South America.Type species.Braga nasuta Schiödte & Meinert, 1881.Other species.Braga amapaensisThatcher, 1996; B. bachmanni Stadler, 1972; B. brasiliensis Schiödte & Meinert, 1981; B.  cichlae Schiödte & Meinert, 1881; B. fluviatilis Richardson, 1911;  B. patagonica Schiödte & Meinert, 1884.