Resumo
Biotodomella gen. nov. (Monogenoidea: Dactylogyridae) is proposed to accommodate Biotodomella mirospinata sp. nov., found on the gills of Biotodoma cupido (Heckel, 1840) (cara bonita or green-streaked eartheater), a freshwater cichlid from the Peruvian Amazon. The new genus and species differ from other Neotropical dactylogyrids in having the hooks of each hook pair well-differentiated from the remaining pairs, shafts varying in robustness, weakly sclerotized expansions at the proximal end of shaft, and a dorsal anchor with grooved shaft, bifid point. This study represents the first record of a monogenoid from a species of Biotodoma Eigenmann & Kennedy, 1903.
Assuntos
Animais , Ciclídeos/parasitologia , Platelmintos/anatomia & histologia , Platelmintos/classificaçãoResumo
Biotodomella gen. nov. (Monogenoidea: Dactylogyridae) is proposed to accommodate Biotodomella mirospinata sp. nov., found on the gills of Biotodoma cupido (Heckel, 1840) (cara bonita or green-streaked eartheater), a freshwater cichlid from the Peruvian Amazon. The new genus and species differ from other Neotropical dactylogyrids in having the hooks of each hook pair well-differentiated from the remaining pairs, shafts varying in robustness, weakly sclerotized expansions at the proximal end of shaft, and a dorsal anchor with grooved shaft, bifid point. This study represents the first record of a monogenoid from a species of Biotodoma Eigenmann & Kennedy, 1903.(AU)
Assuntos
Animais , Ciclídeos/parasitologia , Platelmintos/anatomia & histologia , Platelmintos/classificaçãoResumo
Ergasilus von Nordmann, 1832 is the type and the most speciose genus of Ergasilidae, with more than 150 valid species. The first species of this genus, Ergasilus iheringi Tidd, 1942, was described from the Neotropical Region, from the gills of Hoplias malabaricus (Bloch, 1794). Since then, 35 new species of Ergasilidae have been described from the Neotropics. However, a reanalysis of the available type specimens of E. iheringi revealed features that suggest that it represents a lineage independent from Ergasilus. Consequently, we propose Tiddergasilus gen. nov. (Ergasilidae: Cyclopoida) to accommodate T. iheringi (Tidd, 1942) comb. nov. The species was re-examined and redescribed based on available type specimens. Tiddergasilus gen. nov. is characterized by species with exopod of leg 4 2-segmented; antenna small and robust, with a short second segment (approximately three times shorter than the first segment), and claw with a unique morphology (short, recurved with a sub-proximal indentation in the inner margin). A phylogenetic analysis, based on a matrix of 15 taxa and 16 morphological characters in PAUP* software 4.0a152, resulted in 15 equally parsimonious trees. Based on this analysis, Tiddergasilus is closely related to a group composed of Neotropical species of Ergasilus - sharing with them antennule with 6-segments. When the highly homoplastic character number of segments in the antennule is removed from the analysis, Tiddergasilus forms a polytomy with the clade of genera of the former Vaigamidae, Ergasilus, and the clade Rhinergasilus+Brasergasilus+Pindapixara.
Assuntos
Animais , Biodiversidade , Copépodes/anatomia & histologia , Copépodes/classificação , Especificidade da EspécieResumo
Ergasilus von Nordmann, 1832 is the type and the most speciose genus of Ergasilidae, with more than 150 valid species. The first species of this genus, Ergasilus iheringi Tidd, 1942, was described from the Neotropical Region, from the gills of Hoplias malabaricus (Bloch, 1794). Since then, 35 new species of Ergasilidae have been described from the Neotropics. However, a reanalysis of the available type specimens of E. iheringi revealed features that suggest that it represents a lineage independent from Ergasilus. Consequently, we propose Tiddergasilus gen. nov. (Ergasilidae: Cyclopoida) to accommodate T. iheringi (Tidd, 1942) comb. nov. The species was re-examined and redescribed based on available type specimens. Tiddergasilus gen. nov. is characterized by species with exopod of leg 4 2-segmented; antenna small and robust, with a short second segment (approximately three times shorter than the first segment), and claw with a unique morphology (short, recurved with a sub-proximal indentation in the inner margin). A phylogenetic analysis, based on a matrix of 15 taxa and 16 morphological characters in PAUP* software 4.0a152, resulted in 15 equally parsimonious trees. Based on this analysis, Tiddergasilus is closely related to a group composed of Neotropical species of Ergasilus - sharing with them antennule with 6-segments. When the highly homoplastic character number of segments in the antennule is removed from the analysis, Tiddergasilus forms a polytomy with the clade of genera of the former Vaigamidae, Ergasilus, and the clade Rhinergasilus+Brasergasilus+Pindapixara.(AU)
Assuntos
Animais , Copépodes/anatomia & histologia , Copépodes/classificação , Biodiversidade , Especificidade da EspécieResumo
The production of hybrids of the 'pintado', Pseudoplatystoma corruscans (Spix & Agassiz, 1829) and 'cachara', Pseudoplatystoma reticulatum (Eigenmann & Eigenmann, 1889) in captivity has generated many concerns about the possibility of introduction of farmed hybrids into natural environments. In the last decade, hybrids between these species, known as 'pintachara' or 'cachapinta', were reported from different regions of the Upper Paraná River basin. Prospection of these hybrids is important in order to orient conservation programs for the species involved. Knowledge of the presence of these hybrids will direct conservation strategies towards prevention and/or mitigation of the effects of cross breeding in natural populations of P. corruscans (the native species of the genus) and farmed hybrids. In this study, surveyed the larval population using molecular tools to detect the presence and assess the origin (natural hybridization or escapes from fish farms) of hybrids in natural water bodies. Nine microsatellite markers were used to detect signals of hybridization and introgression of P. reticulatum in larvae and adults of P. corruscans in Upper Paraná River basin, between Itaipu Dam and Porto Primavera Dam. The specimens were sampled in the Upper Paraná channel and in tributaries where hybrids had been detected in the past, during two reproductive seasons. Despite of that, no sign of hybridization and introgression was found in the 171 larvae and 75 adults sampled, suggesting that the specimens detected in previous studies had originated from escapes of aquaculture farms.
Assuntos
Animais , Hibridização Genética/genética , Peixes-Gato/genética , Repetições de Microssatélites/genética , Transferência Genética HorizontalResumo
The production of hybrids of the 'pintado', Pseudoplatystoma corruscans (Spix & Agassiz, 1829) and 'cachara', Pseudoplatystoma reticulatum (Eigenmann & Eigenmann, 1889) in captivity has generated many concerns about the possibility of introduction of farmed hybrids into natural environments. In the last decade, hybrids between these species, known as 'pintachara' or 'cachapinta', were reported from different regions of the Upper Paraná River basin. Prospection of these hybrids is important in order to orient conservation programs for the species involved. Knowledge of the presence of these hybrids will direct conservation strategies towards prevention and/or mitigation of the effects of cross breeding in natural populations of P. corruscans (the native species of the genus) and farmed hybrids. In this study, surveyed the larval population using molecular tools to detect the presence and assess the origin (natural hybridization or escapes from fish farms) of hybrids in natural water bodies. Nine microsatellite markers were used to detect signals of hybridization and introgression of P. reticulatum in larvae and adults of P. corruscans in Upper Paraná River basin, between Itaipu Dam and Porto Primavera Dam. The specimens were sampled in the Upper Paraná channel and in tributaries where hybrids had been detected in the past, during two reproductive seasons. Despite of that, no sign of hybridization and introgression was found in the 171 larvae and 75 adults sampled, suggesting that the specimens detected in previous studies had originated from escapes of aquaculture farms.(AU)
Assuntos
Animais , Peixes-Gato/genética , Hibridização Genética/genética , Repetições de Microssatélites/genética , Transferência Genética HorizontalResumo
A new genus and species of Monogenoidea, Susanlimae ianwhittingtoni gen. nov., sp. nov., are proposed for dactylogyrids collected from the "Nuayang tipis", Pseudeutropius moolenburghae Weber & de Beaufort, 1913, which inhabits freshwater in Sumatra. While clearly a member of a putative clade that includes Asian and African catfish parasites, S. ianwhittingtoni sp. nov. differs from most members of this clade by having a bifurcated haptor that embraces the gill rakers of its host. This haptoral morphology and mode of attachment also occur in species of Bifurcohaptor Jain, 1958. However, species of Susanlimae gen. nov. are easily distinguished by the comparative morphology of their haptoral armature. In Susanlimae gen. nov., the ventral and dorsal bars are single, elongated, and inverted u-shaped (ventral bar short and two short dorsal bars in Bifurcohaptor spp.); the dorsal anchor is robust with well-defined roots (reduced roots and elongate shaft in Bifurcohaptor spp.); and the ventral anchor has an elongated, deep root (inconspicuous in Bifurcohaptor spp.).
Assuntos
Animais , Biodiversidade , Ectoparasitoses/veterinária , Peixes-Gato , IndonésiaResumo
A new genus and species of Monogenoidea, Susanlimae ianwhittingtoni gen. nov., sp. nov., are proposed for dactylogyrids collected from the "Nuayang tipis", Pseudeutropius moolenburghae Weber & de Beaufort, 1913, which inhabits freshwater in Sumatra. While clearly a member of a putative clade that includes Asian and African catfish parasites, S. ianwhittingtoni sp. nov. differs from most members of this clade by having a bifurcated haptor that embraces the gill rakers of its host. This haptoral morphology and mode of attachment also occur in species of Bifurcohaptor Jain, 1958. However, species of Susanlimae gen. nov. are easily distinguished by the comparative morphology of their haptoral armature. In Susanlimae gen. nov., the ventral and dorsal bars are single, elongated, and inverted u-shaped (ventral bar short and two short dorsal bars in Bifurcohaptor spp.); the dorsal anchor is robust with well-defined roots (reduced roots and elongate shaft in Bifurcohaptor spp.); and the ventral anchor has an elongated, deep root (inconspicuous in Bifurcohaptor spp.).(AU)
Assuntos
Animais , Peixes-Gato , Biodiversidade , Ectoparasitoses/veterinária , IndonésiaResumo
One of the most limiting factors affecting the larval rearing of Ucides cordatus in the laboratory is a period of high mortality, which usually occurs late in the course of the larviculture during the metamorphosis from the zoeal to the megalopal phase. The objective of the present research was to analyze the post-embryonic development of U. cordatus on an individual basis and, in particular, to search for patterns linking disturbances in the molting process to the high larval death rates observed in massive larvicultures. A total of 50 larvae were individually reared from hatching to metamorphosis into the megalopal phase under controlled conditions, fed a combination of microalgae and rotifers. The survivorship rate was 70% until zoea V. The 35 surviving zoea V larvae followed two different pathways. Eleven underwent metamorphosis directly to megalopa, eighteen molted to zoea VI and six died as zoea V. In the last molting event, only two zoea VI larvae reached the megalopal stage, while the remaining sixteen died. In further observation under microscope, 13 of the dead zoea VI showed characteristics of the pre-molt stage and pereiopods disproportionably large in relation to the carapace. The observed pattern resembles the Molt Death Syndrome (MDS) described for other decapod species, in which larvae die in the late pre-molt phase of the molting cycle. We suggest that U. cordatus larvae develop disturbances in the molting process similar to the MDS described for other species and that these disturbances are related to a more complex pathway involving the emergence of larval stage zoea VI.(AU)
Um dos fatores mais limitantes que afetam o cultivo larval de Ucides cordatus (Linnaeus, 1763) em laboratório é um período de alta mortalidade, o qual usualmente ocorre no fim do curso da larvicultura durante a metamorfose da fase de zoea para a de megalopa. O objetivo da presente pesquisa foi analisar o desenvolvimento pósembrionário de U. cordatus em uma base individual e, em particular, procurar por padrões ligando distúrbios no processo de muda com as altas taxas de mortalidade observadas nas larviculturas massivas. Um total de 50 larvas foram cultivadas individualmente da eclosão até a fase de megalopa em condições controladas, alimentadas com uma combinação de microalgas e rotíferos. A taxa de sobrevivência foi de 70% até zoea V. As 35 larvas zoea V sobreviventes seguiram dois diferentes caminhos. Onze realizaram a metamorfose diretamente para megalopa, dezoito mudaram para zoea VI e seis morreram como zoea V. No último evento de muda, apenas duas larvas zoea VI atingiram a fase de megalopa, enquanto as dezesseis restantes morreram. Em investigação posterior sob microscópio, 13 das zoea VI mortas mostravam características de estágio de prémuda e pereiópodes desproporcionalmente grandes em relação à carapaça. O padrão observado lembra a Síndrome da Morte na Muda (MDS) descrita para outras espécies de decápodes, na qual larvas morrem no fim da fase de prémuda do ciclo de mudas. Nós sugerimos que larvas de U. cordatus desenvolvem distúrbios no processo de muda similares à MDS descrita para outras espécies e que esses distúrbios são relacionados a um caminho mais complexo que envolve a ocorrência do estágio larval zoea VI.(AU)