RESUMO
In this study, a new species of Pseudogilbia Møller, Schwarzhans & Nielsen 2004 is described based on two male specimens (40-44 mm LS ) from shallow reefs of Bahia, Brazil. Pseudogilbia australis sp. nov. is distinguished from its only congener, Pseudogilbia sanblasensis Møller, Schwarzhans & Nielsen 2004 from Caribbean Panama, by having: two lower preopercular pores (vs. one); dorsal-fin rays 65-67 (vs. 69); anal-fin rays 51-53 (vs. 56); pectoral-fin rays 18 (vs. 20); caudal vertebrae 27-28 (vs. 30); pectoral-fin length 15.0%-15.9% LS (vs. 14.3); pelvic-fin length 13.5% LS (vs. 16.4) and a different morphology of the male copulatory organ. Pseudogilbia australis sp. nov. is the only dinematichthyid so far recorded in the South Atlantic. An updated diagnosis for the genus is also provided.
Assuntos
Perciformes , Animais , Brasil , Região do Caribe , Peixes , Masculino , PanamáRESUMO
A new species of Acropomatid fish, Verilus costai sp. nov., is described from a single locality off Belmonte, State of Bahia, Brazil. It resembles Verilus pseudomicrolepis (Schultz, 1940) from the Caribbean Sea. The two are considered vicariant and they are interpreted to be separated from other species of the genus Verilus by (amongst other characters) the presence of fangs on the dentary (vs. only villiform teeth), the anal fin formula (II+9 vs. III+7) and the naked occiput (vs. scaled). However, formal establishment of a separate genus is postponed until a complete phylogenetic review of the family has been performed. Verilus costai can be distinguished from V. pseudomicrolepis by its higher number of gill rakers (27-31 vs. 21-25), lower number of pseudobranchial filaments (15-23 vs. 21-28), shorter snout length (8.2-11.3 vs. 11.3-13.4 % of SL), and more compressed otoliths (OL:OH = 1.3-1.35 vs. 1.35-1.5). In addition, the fossil otolith-based species Verilus mutinensis (Bassoli, 1906) from the late Miocene to middle Pleistocene of the Mediterranean is thought to be related and indicates that in the past this group was more widely distributed than nowadays and comprised more vicariant species.
Assuntos
Perciformes , Animais , Brasil , Peixes , FilogeniaRESUMO
An ongoing review of the fishes of the basal percoid family Acropomatidae has revealed that the genus Synagrops Günther, 1887 as it is currently understood is not a natural group. Species with a serrated pelvic-fin spine are here placed in the resurrected genus Parascombrops Alcock, 1889 (type-species: Parascombrops pellucidus Alcock, 1889), and the new, monospecific genus Caraibops n. gen. (type-species: Synagrops trispinosus Mochizuki & Sano, 1984). Parascombrops is unique amongst Acropomatidae in the combination of the presence of vacant 8th interneural space, a predorsal formula /0+0/0+2/ and an epaxialis attachment type 1. Caraibops n. gen. shares none of these characters and further differs from Parascombrops by an anal-fin formula of III + 9 (vs II + 7 or III + 6), and the absence of denticles on the ectopterygoid. Parascombrops is revised and now contains a total of 13 species, including 7 new: P. analis (Katayama, 1957), P. argyreus (Gilbert & Cramer, 1897), P. glossodon n. sp., P. madagascariensis n. sp., P. mochizukii n. sp., P. nakayamai n. sp., P. ohei n. sp., P. parvidens n. sp., P. pellucidus Alcock, 1889, P. philippinensis (Günther, 1880), P. serratospinosus (Smith & Radcliffe, 1912), P. spinosus (Schultz, 1940) and P. yamanouei n. sp. Synagrops adeni Kotthaus, 1970 and S. malayanus Weber, 1913 are treated as synonyms of P. pellucidus and P. philippinensis, respectively. Lectotypes are designated for P. philippinensis and S. malayanus. The main characters used to distinguish between the species of Parascombrops are: serration of other fin spines, number of gill rakers and pseudobranchial filaments, head profile, presence or absence of ridges on the preopercle, shape of 1st anal-fin pterygiophore, dentition on vomer, palatines and ectopterygoids, orbit diameter, pectoral-fin length, maximal body depth and otolith morphology. The genus Synagrops is here confined to two species, S. japonicus (Döderlein, 1883) and S. bellus (Goode & Bean, 1896), characterized by the apomorphic character of an otic capsule with a posteriorly open myodome, a basioccipital fossa and a very specialized otolith morphology. Synagrops is also characterized by the absence of pelvic-fin spine serrations. Two other species without a serrated pelvic-fin spine, originally described in Synagrops, are removed from this genus. Synagrops microlepis Norman, 1935 is separated into the monotypic Kaperangus n. gen., the only genus in the family with two supraneurals (cf. three in all other taxa). The second, Synagrops pseudomicrolepis Schultz, 1940 is re-assigned to the genus Verilus. The geographic distribution of Parascombrops as currently composed is discussed, and is shown to be primarily of West Pacific nature, with few species in the Indian Ocean and one in the tropical West-Atlantic (P. spinosus). The West Atlantic species Parascombrops spinosus is very closely related to P. mochizukii from the tropical northwestern Pacific, and the implications of this disjunct distribution are discussed. The high degree of speciation now recognized in Parascombrops species of the West-Pacific indicates that a diverse ecological adaptation within an overall pseudoceanic habitat may have played a major role in speciation, which would have remained obscured without adequate taxonomic resolution. Fossil, otolith-based records are also briefly discussed in the context. The extant Parascombrops argyreus and P. ohei are reported from the Pliocene of Japan, and Caraibops trispinosus has been recorded from the Pliocene of Venezuela.