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.

Ergasilus chelangulatus sp. nov. é descrita do peixe de água doce, Pimelodus maculatus Lacépède, 1803 (Siluriformes: Pimelodidae) do alto rio São Francisco, Minas Gerais, Brasil. A nova espécie está baseada em espécimes fêmeas e o macho é desconhecido. Esta espécie tem uma seta serrilhada no primeiro exopodito e tem o primeiro endopodito bi-segmentado, como a maioria das espécies amazônicas deste gênero. O corpo é alongado e projetado anteriormente. As antenas são alongadas com sensila proeminente no segundo e no terceiro segmentos. Ergasilus chelangulatus sp. nov. é distinta de todas as outras espécies conhecidas de Ergasilus por ter o quarto segmento antenal (garra) dobrado em ângulo quase reto.

Ergasilus chelangulatus sp. nov. is described from the freshwater fish, Pimelodus maculatus Lacépède, 1803 (Siluriformes: Pimelodidae) of the upper São Francisco River, Minas Gerais State, Brazil. The new species is based on female specimens and the male is unknown. This species has a serrate seta on exopod one and a two-segmented first endopod, as do most Amazonian species of this genus. The body is elongate and produced anteriorly. The antennae are elongate and have prominent sensilla on segments two and three. Ergasilus chelangulatus sp. nov. can be distinguished from all known species of Ergasilus by the fourth antennal segment (claw) which is bent at nearly a right angle.

Ergasilus salmini sp. nov. um parasito das brânquias do "dourado", Salminus franciscanus Lima & Britski, 2007, do alto rio São Francisco, Minas Gerais, Brasil, é descrita baseada em espécimes fêmeas. A nova espécie tem uma seta curva, serrilhada, no primeiro exopodito como a maioria das espécies conhecidas deste gênero. A maioria dos ergasilídeos tem a cabeça e os dois primeiros segmentos torácicos completamente fusionados formando o cefalotórax. Na nova espécie, a cabeça é incompletamente fusionada, o primeiro segmento torácico é fusionado, mas o segundo segmento torácico é livre. Ergasilus hydrolycus Thatcher, Boeger & Robertson, 1984, também possui o segundo segmento torácico livre mas nessa espécie a cabeça é completamente fusionada e o terceiro segmento abdominal é o mais comprido. Na nova espécie, o terceiro segmento é o mais curto dos três. A nova espécie também é menor medindo 691 x 207 ìm comparado com 784 x 278 ìm em E. hydrolycus. Essa espécie tem o quarto endopodito bi-segmentado enquanto na nova espécie essa estrutura é tri-segmentada. Adicionalmente, a nova espécie é de um hospedeiro diferente e de um sistema hídrico distinto.

Ergasilus salmini sp. nov. a branchial parasite of the "dourado", Salminus franciscanus Lima & Britski, 2007, from the upper São Francisco river, Minas Gerais State, Brazil, is described based on female specimens. The new species has a serrate, curved seta on the first exopod as do most of the known South American species of the genus. Other than that, it does not closely resemble any known species of this genus. Many of the known ergasilids have head, and first two thoracic segments completely fused to form a cephalothorax. In the new species, the head is incompletely fused, the first thoracic segment is fused, but thoracic segment two is free. Ergasilus hydrolycus Thatcher, Boeger & Robertson, 1984, also has a free second thoracic segment but in that species the head is completely fused and the third abdominal segment is the longest. In the new species, the third segment is the shortest of the three. Also, the new species is smaller averaging 691 x 207 µ m compared to 784 x 278 µ m for E. hydrolycus. The latter species has a two-segmented fourth endopod whereas in the new species this structure is three-segmented. In addition, the new species is from a different host and a separate river system.

Cymothoa spinipalpa sp. nov. (Isopoda, Cymothoidae), um parasito da cavidade bucal do peixe marinho, Oligoplites saurus, é descrita baseada em oito espécimes machos e uma fêmea Os peixes foram capturados nas águas costeiras de Natal, Rio Grande do Norte, Brasil. Na nova espécie, a margem anterior do cefalon é dobrada ventralmente sobre as bases das antenas. Neste aspecto, ela assemelha-se a C. recifea Thatcher & Fonseca, 2005. Distingue-se dessa espécie, no entanto, pelo menor tamanho e pelas carinas dos pereópodos 4 a 7 que são relativamente pequenas e arredondadas (não grandes e ponte agudas). Aliás, os pleópodos 2-4 carecem das dobras e bolsos que são presentes em C. recifea. Cymothoa spinipalpa sp. nov. distingue-se de todas as demais espécies de Cymothoa por ter palpos mandibulares completamente cobertos por espinhos nos machos adultos. As mancas têm antenas compridas e por isso parecem com as de Cymothoa oestrum mas distinguem-se por serem mais largas e de terem urópodos mais curtos.

Cymothoa spinipalpa sp. nov. (Isopoda, Cymothoidae) a buccal cavity parasite of the marine fish, Oligoplites saurus, is described on the basis of eight male specimens and one female. The fish hosts were captured in the coastal waters of Natal, Rio Grande do Norte State, Brazil. In the new species, the anterior margin of the cephalon is doubled ventrally over the bases of the antennae. In this respect, it resembles C. recifea Thatcher & Fonseca, 2005. It differs from that species, however, in being much smaller and having basal carinae on the pereopods 4 to 7 that are small and rounded (not large and pointed). Also, pleopods 2-4 lack the folds and pockets that are present in C. recifea. The new species can be distinguished from all known Cymothoa spp. by the mandibular palps which are entirely covered with small spines in adult males. The mancas of the new species resemble those of Cymothoa oestrum since they have elongate antennae but they are wider and have shorter uropods.

Kroyeria brasiliense sp. nov. proveniente de guelras de G. vitaminicus de Buen, 1950 do Rio Grande do Sul, é descrita baseada em 14 fêmeas adultas. A nova espécie aproxima-se de Kroyeria deetsi Dippenaar, Benz & Oliver, 2000, mas a nova espécie se distingue por apresentar os maxilípedes grandes e estendendo-se bem além das margens do cefalotorax. Os terceiros segmentos dos endopoditos de K. deetsi são duas vezes mais cumpridos que os segundos e têm dentículos marginais proeminentes. Os segundos e terceiros segmentos dos endopoditos da nova espécie são arredondados, de tamanhos parecidos e carecem de dentículos.

Kroyeria brasiliense sp. nov. from the shark, Galeorhinus vitaminicus de Buen, 1950, from Rio Grande do Sul, State, Brazil, is described on the basis of 14 adult females. The new species is superficially similar to Kroyeria deetsi Dippenaar, Benz & Olivier, 2000, but differs from it in the following characters. The maxillipeds of the new species are large and project well beyond the lateral margins of the cephalothorax. Those of K. deetsi are much smaller. The third endopodal segments of K. deetsi are twice as long as the second endopodal segments and are provided with prominent marginal denticles. The second and third endopodal segments of the new species are rounded, of similar length and lack teeth.

Entre Isopodas Crustaceas existem ectoparasitos que são de fácil observação devido ao seu tamanho. Eles causam lesões mecânicas no hospedeiro que podem resultar em morte. Este trabalho verificou a existência de parasitismo por isópodos no peixe serra, Scomberomorus brasiliensis (Collette, Russo & Zavala-Camin, 1978) das águas costeiras do Rio Grande do Norte, Brasil. Os índices de infestação parasitária dos isópodos foram calculados e relacionados com o tamanho, peso e o estado gonadal do hospedeiro. Livoneca redmanni (Leach, 1818) (Cymothoidae) e Rocinela signata (Schioedte & Meinert, 1879) (Aegidae) foram registradas pela primeira vez nas águas costeiras do Rio Grande do Norte. Os locais de fixação de L. redmanni no hospedeiro foram a cavidade bucal e a câmara branquial, enquanto R. signata sempre foi encontrada na câmara branquial. Dos exemplares de S. brasiliensis capturados 31 % estavam parasitados, onde 86 % eram de L. redmanni e 14 % de R. signata. Foi registrado uma intensidade mínima de um e máxima de quatro isópodos por hospedeiro. Os isópodos apresentaram uma preferência pelos hospedeiros imaturos e em maturação de S. brasiliensis.

Among the crustacean isopoda there exists ectoparasites which are easy to observe due to their size. They cause lesions on the host that could lead to death. The present study verified the occurrence of parasitic isopods on the fish Serra Spanish mackerel, Scomberomorus brasiliensis (Collette, Russo & Zavala-Camin, 1978) from the coastal waters of Rio Grande do Norte, Brazil. Indices of parasitic infection by isopods were calculated and correlated to the body size, weight and the stage of gonadal maturity of the host. Livoneca redmanni (Leach, 1818) (Cymothoidae) and Rocinela signata (Schioedte & Meinert, 1879) (Aegidae) were registered for the first time in the coastal waters of Rio Grande do Norte. L. redmanni was encountered both in the oral cavity and in the gill chambers of the host, whereas R. signata was found only in the gill chambers. Parasitic isopods were encountered on 31% of S. brasiliensis captured, wherein 86% was L. redmanni and 14% was R. signata. The maximum parasitic intensity was four with a minimum of one isopods per host. The isopods showed a preference for immature and maturing stages of the host S. brasiliensis.

Minilernaea floricapitella gen. nov., sp. nov. (Copepoda, Cyclopoida, Lernaeidae) um parasito dos peixes, Astyanax spp. and Corydoras ehrhardti Regan, 1912 dos estados de Santa Catarina e Paraná, Brasil, é descrita baseada em 10 fêmeas pós-metamórficas. O novo gênero e espécie tem as seguintes características que servem para distingui-la dos demais lerneídeos: (1). O corpo é muito pequeno (3.4-5.8 mm de comprimento); (2) A cabeça é provida anteriormente com seis lóbulos e posteriormente com quatro âncoras não divididas; (3) O primeiro par de toracópodos encontra-se na cabeça, quando 2-4 estão no pescoço; Toracópodo 5 é reduzido a uma papila simples perto dos poros genitais; (5) Os poros genitais são localizados na área equatorial do corpo posterior e não existe uma proeminência pre-genital. Já que a cabeça e uma parte do pescoço são inseridas sob a pele, o hospedeiro demostra uma reação encapsuladora forte.

Minilernaea floricapitella gen. nov., sp. nov. (Copepoda, Cyclopoida, Lernaeidae) a parasite of the freshwater fishes, Astyanax spp. and Corydoras ehrhardti Regan, 1912 of Santa Catarina and Paraná States, Brazil, is described, based on 10 postmetamorphic females. The new genus and species has the following characteristics that distinguish it from all other known lernaeids: (1) The body is very small (3.4-5.8 mm in length); (2) The head is provided anteriorly with six lobes and posteriorly with four undivided anchor arms. (3) The first pair of thoracopods is on the head, 2-4 are all on the "neck"; (4) Thoracopod 5 is reduced to a simple papillus near the genital pores; (5) The genital pores are equatorial in the hindbody and there is no pre-genital prominence. Since the head and part of the neck are inserted beneath the skin, the host produces a strong encapsulating reaction.

Cymothoa recifea sp. nov. (Isopoda, Cymothoidae) é descrito das bocas de Centropomus undecimalis (Bloch, 1792) e Oligoplites palometa (Cuvier, 1832). Os peixes foram capturados perto de Itamaracá, Estado de Pernambuco, Brasil. A nova espécie apresenta uma semelhança superficial à Cymothoa oestrum (Linnaeus, 1793) da qual distingue-se pôr várias características. Na nova espécie, as expansões nas bases dos pereópodos ("carinae") são grandes nos 4-7 e, geralmente, terminam em pontas agudas. Em contraste, em C. oestrum, estas estruturas são pequenas nos pereópodos 4-6, grande somente no sétimo e não têm pontas agudas. Na nova espécie, somente o pleópodo 1 é simples e 2-5 apresentam bolsas e dobras. Na outra espécie, os pleópodos 1-4 são simples e somente 5 tem dobras.

Cymothoa recifea sp. nov. (Isopoda, Cymothoidae) is described from the mouths of Centropomus undecimalis (Bloch, 1792) and Oligoplites palometa (Cuvier, 1832). The fish hosts were caught near Itamaracá and Cabo de Santo Agostinho, State of Pernambuco, Brazil. The new species bears a superficial resemblance to Cymothoa oestrum (Linnaeus, 1793) from which it differs in a number of important respects. In the new species, the basal carinae are large on pereopods 4-7 and usually pointed, whereas in C. oestrum the carinae are small on pereopods 4-6, large on 7 and not pointed. In the new species, only pleopod 1 is simple and 2-5 are provided with pockets and folds. In the other species, pleopods 1-4 are simple and only 5 has folds.

Brasilochondria riograndensis gen. nov., sp. nov. (Copepoda, Chondracanthidae), um parasito do linguado, Paralichthys orbignyanus (Valenciennes, 1839), é descrito. O novo gênero tem uma cabeça esférica, um "pescoço" pós-mandíbular e dois pares de pernas que são birremes e modificados na fêmea. Nestes aspectos, ela parece com Argentinochondria patagonensis Etchegoin, Timi & Sardella, 2003. Nesta, no entanto, a cabeça é esférica com uma constrição medial e na parte posterior do tronco faltam as extensões póstero-laterais que o novo gênero possui. Pseudolernentoma brasiliensis Luque & Alves, 2003, é também parecido com o novo gênero, mas carece das extensões póstero-laterais e o mesmo tronco é cilíndrico em vez de achatado. A segunda perna no novo gênero é pequena e o endopodito é mais curto que o exopodito. Nos outros dois gêneros, as segundas pernas são grandes e os ramos são sub-iguais.

Brasilochondria riograndensis gen. nov., sp. nov. (Copepoda, Chondracanthidae) a parasite of the flounder, Paralichthys orbignyanus (Valenciennes, 1839), is described. The new genus has a spherical head a post-mandibular "neck" and two pairs of modified biramous legs. In these respects, it resembles Argentinochondria patagonensis Etchegoin, Timi & Sardella, 2003. In the Argentine genus, however, the bulbous head has a medial constriction and the posterior of the female lacks the lateral extensions that are present in the new genus. Pseudolernentoma brasiliensis Luque & Alves, 2003, also resembles the new genus but it lacks the lateral extensions of the trunk and the latter is cylindrical rather than flat. The second leg of the new genus is small and the endopod is shorter than the exopod. The other two genera have large second legs with subequal rami.

Cymothoa catarinensis sp. nov. collected at Camboriú, Santa Catarina State, Brazil is described. The new species is of small size, has a cephalon that is little immersed in pereonite 1, anterolateral angles of pereonite 1 that reach or surpass the eyes and a pleon that is deeply immersed in pereonite 7. The pleopods of the new species have small, lobular accessory gills projecting from the bases. Cymothoa excisa Perty, 1830, and Cymothoa oestrum (Linnaeus, 1758) are redescribed. Both are of large size (25-35 mm in length). C. excisa has pointed anterolateral margins of pereonite 1 that reach or surpass the eyes. This species also has trilaminate pleopods in the female and bilaminate pleopods in the male. C. oestrum has rounded anterolateral margins of pereonite 1 and no visible eyes. This is the first time the latter species has been reported from Brazil. These three species are compared to four others that have been reported from Brazilian waters, namely: C. liannae Sartor & Pires, 1988; C. brasiliensis, C. gerris and C. ianuarii, all described by Schiödte & Meinert, 1884. A key is provided to aid in the separation of the Brazilian species of Cymothoa.

Lironeca desterroensis sp. nov. (Isopoda, Cymothoidae) is described on the basis of 105 females and three males taken from the gill chambers of the marine fish, Cetengraulis edentulus (Cuvier,1829), obtained near Santa Catarina Island, Brazil. The new species resembles Lironeca redmanni Leach, 1818, in size and general appearance but differs from that species in a number of important respects. In the new species, the pleotelson is larger, the pleonites are laterally produced, the uropods have elongate and slender rami and the larval stage (Pullus II) has a prominent frontal projection.

Riggia cryptocularis sp. nov. (Isopoda, Cymothoidae) is described on the basis of one female and one male specimen from the body cavity of freshwater fish from Mato Grosso do Sul State, Brazil. The new species is similar in size to R. paranensis Szidat, 1948, but differs from that species in the following respects. The body shapes are different since the widest part of the adult female is more anterior in R. paranensis. The eyes of the new species are covered and non-functional unlike those of the other species. The cephalon of the new species has a postero-dorsal elevation and a rounded and depressed frons which are lacking in the other species. Pereonites 5-7 are subequal in length in the new species and decrease in length in R. paranensis. The pleon/pleotelson tapers in the female of the new species and in the other it is bluntly rounded and with nearly parallel sides. The pleopods of R. cryptocularis sp. nov. also taper while those of R. paranensis are rounded. The recently described species, R. acuticaudata Thatcher, Lopes & Froehlich, 2002, was also obtained in Mato Grosso do Sul State but differs greatly from the presently described species. The body of R. acuticaudata is much smaller, and more rounded. The eyes of this species are large and functional, the dorsum of the cephalon lacks a dorsal prominence and the pleon/pleotelson tapers more abruptly.

Anphira guianensis sp. nov. (Isopoda, Cymothoidae) is described from the branchial cavity of a freshwater fish, Acnodon oligacanthus Eigenmann, 1903 from French Guiana. The new species differs from the other known species of the genus in a number of important respects. Adult females are less convex than those of the other two known species and the mouth points downward. The coxal plates are largest posteriorly, unlike those of the other species. The antennule is much stouter and longer than the antenna whereas in the other species these appendages are subequal. Additionally, the dactyls of the new species are much longer.

Riggia acuticaudata sp. nov. is described on the basis of 10 female specimens recovered from the body cavity of the freshwater catfish, Ancistrus sp. The fish were caught in a stream called the Corrego Piraputanga, a tributary of the Paraguai River. The new species differs from the others in the genus by being smaller and less convex and by having a pleotelson that tapers abruptly rather than being the same width throughout. Also, the pereopods and dactyls are much smaller, the maxillule has two terminal and three subterminal spines and the first two pleopods are elongate and acute. Additionally, R. acuticaudata sp. nov. is from a different Order of fish host and a new geographic area.

Brasacanthus sphoeroides gen. n.. sp. n. is described from the marine fish, Sphoeroides greeleyi (Steindachner), taken in Paranaguá Bay, Paraná State, Brazil. The new genus differs from Acanthocephalus Koelreuter, 1771, the nearest genus in the family Echinorhynchidae, by having very flat and variable lemnisci in both sexes and a uterine egg reservoir in the female. The species is characterized by its spherical body form and in having parallel or diagonal testes.