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This study aimed to describe the early development of Clarias gariepinus, a species that has been introduced into various watersheds worldwide, in order to help the identification of its eggs, larvae and juveniles in natural environments. The material used was obtained via induced spawning during 1999. After spawning, the periodicity of sampling varied according to ontogenic development. We analyzed 12 eggs, 146 larvae and 6 juveniles. Newly fertilized eggs are spherical, with a double membrane, the density of which varies. Initially the larvae have little pigmentation but this intensifies during development. They have four pairs of well-developed barbels, an elongated body, long dorsal and anal fins, no adipose fin and vesicles surrounding the finfold and barbels. The sequence of formation of the fins is: caudal, dorsal, anal, pectoral and pelvic. Growth pattern analysis revealed that metamorphosis usually occurs during the flexion stage. The reproductive performance of the species and its rapid early development favor aquaculture; however, they may also favor its invasion of natural environments, representing a threat for native populations.

The present study characterizes the early stages of development of Brycon hilarii (Valenciennes, 1850) based on morphometric and meristic characters. Patterns of development in morphometric characters were analyzed through the fit of linear, quadratic and linear piecewise models. Samples were collected from March 2000 to March 2004 in basins of the Cuiaba and Manso rivers, state of Mato Grosso, Brazil. Larvae were identified and classified in different stages (Larval Yolk, Pre-Flexion, Flexion, and Post-Flexion) according to notochord development. The morphometric and meristic characters for each larva were, respectively, measured and counted. The standard length ranged from 3.25 to 26.00 mm. The Larval Yolk stage showed a greater concentration of dendritic pigments along the intestine, and the Flexion and Post-Flexion stages showed an intensified pigmentation intensified along the back. A single spot on the humerus and another on the caudal peduncle were observed at the end of the Post-Flexion stage. Also, in the Larval Yolk and Pre-Flexion stages. The intestine is long, the snout is short, the adhesive organ was present in the Larval Yolk and Pre-Flexion, and the mouth is terminal throughout the development. The total number of myomeres ranged from 41 to 50 (23 to 30 pre-anal and 16 to 24 post-anal). Number of fin rays: dorsal 11; anal 30; pectoral 15 and ventral eight. The analysis of the development indicated higher metamorphosis in the Flexion stage.

O presente estudo caracterizou o desenvolvimento inicial de Brycon hilarii (Valenciennes, 1850) através de caracteres morfométricos e merísticos e analisou as relações entre as características morfométricas das larvas ao longo do desenvolvimento usando modelos de regressão linear, quadrática e linear por partes. O material foi obtido nas bacias dos rios Cuiabá e Manso, Mato Grosso, Brasil, entre março de 2000 e março de 2004. Os indivíduos foram identificados e separados de acordo com o grau de desenvolvimento da notocorda e, posteriormente, medidos e contados os caracteres morfométricos e merísticos, respectivamente. O comprimento padrão variou entre 3,25 e 26,00 mm. Inicialmente, as larvas apresentaram maior concentração de pigmentos dendríticos ao longo do intestino e, em flexão e pós-flexão, intensificaram-se no dorso do corpo. Uma mancha umeral e outra no pedúnculo caudal foram observadas no final do estágio de pós-flexão. O intestino apresentou-se longo, o focinho curto, o órgão adesivo presente em larval vitelino e pré-flexão e a boca terminal por todo o desenvolvimento. O número total de miômeros variou de 41 a 50 (23 a 30 pré e 16 a 24 pós-anal). O número de raios das nadadeiras foi: dorsal 11; anal 30; peitoral 15 e ventral oito. A análise do crescimento indicou maior metamorfose no estágio de flexão. The present study characterizes the early stages of development of Brycon hilarii (Valenciennes, 1850) based on morphometric and meristic characters. Patterns of development in morphometric characters were analyzed through the fit of linear, quadratic and linear piecewise models. Samples were collected from March 2000 to March 2004 in basins of the Cuiabá and Manso rivers, state of Mato Grosso, Brazil. Larvae were identified and classified in different stages (Larval Yolk, Pre-Flexion, Flexion, and Post-Flexion) according to notochord development. The morphometric and meristic characters for each larva were, respectively, measured and counted. The standard length ranged from 3.25 to 26.00 mm. The Larval Yolk stage showed a greater concentration of dendritic pigments along the intestine, and the Flexion and Post-Flexion stages showed an intensified pigmentation intensified along the back. A single spot on the humerus and another on the caudal peduncle were observed at the end of the Post-Flexion stage. Also, in the Larval Yolk and Pre-Flexion stages. The intestine is long, the snout is short, the adhesive organ was present in the Larval Yolk and Pre-Flexion, and the mouth is terminal throughout the development. The total number of myomeres ranged from 41 to 50 (23 to 30 pre-anal and 16 to 24 post-anal). Number of fin rays: dorsal 11; anal 30; pectoral 15 and ventral eight. The analysis of the development indicated higher metamorphosis in the Flexion stage.

Em reservatórios, são escassos os estudos que consideram as fases iniciais do ciclo de vida de peixes, sendo que informações sobre a ecologia de larvas de peixes são úteis para o entendimento da biologia das espécies, visto que os estágios iniciais representam um período crítico no ciclo de vida dos peixes. Neste contexto, o conhecimento a respeito das assembleias de larvas pode ser valioso para a predição e o entendimento do recrutamento, auxiliando desta maneira, no manejo do ambiente. Desta forma, o presente trabalho pretende verificar a composição da assembleia de larvas de peixes em diferentes regiões do reservatório. As coletas foram realizadas trimestralmente (março, junho, setembro e dezembro) no ano de 2002, nas regiões limnética e litorânea das zonas fluvial, transição e lacustre do reservatório de Rosana. No laboratório, o material foi triado e as larvas foram separadas e identificadas ao menor nível taxonômico possível. Os táxons que tiveram maior contribuição na região limnética foram Plagioscion squamosissimus (Perciformes), Hypophthalmus edentatus, Pimelodus maculatus (Siluriformes), Astyanax spp. e Roeboides descalvadensis (Characiformes), enquanto na região litorânea Bryconamericus stramineus e Apareiodon affinis (Characiformes). As regiões limnética e litorânea do reservatório, assim como suas respectivas zonas apresentaram diferenças na composição de espécies de larvas e a segregação das assembleias pode estar sendo influenciada pela preferência por habitats ou por questões evolutivas que envolvem as estratégias reprodutivas das espécies. There are few studies in reservoirs that consider the Early Life Stages (ELS) of fish. Information on the ecology of fish larvae are useful for understanding the biology of the species, since ELS represent a critical period in fish life cycle. In this context, knowledge about the assemblages of larvae can be valuable for the prediction and understanding of recruitment, thus assisting in the management of the environment. Therefore, this study intends to investigate the composition of the assemblage of fish larvae in different regions of Rosana reservoir. Samples were collected quarterly (March, June, September and December) in 2002, in the limnetic and littoral regions of the zones fluvial, transition and lacustrine of reservoir. In the laboratory, the material was sorted and larvae were separated and identified to lowest possible taxonomic level. The taxa that were the major contributors in the limnetic region were Plagioscion squamosissimus (Perciformes), Hypophthalmus edentatus, Pimelodus maculatus (Siluriformes), Astyanax spp. and Roeboides descalvadensis (Characiformes), whereas in the coastal region Bryconamericus stramineus and Apareiodon affinis (Characiformes) prevailed. Limnetic and littoral regions of the reservoir, as well as their respective zones showed differences in larvae species composition and segregation of assemblages can be influenced by a preference for habitats or evolutionary questions involving reproductive strategies of species.

Este trabalho descreve o desenvolvimento inicial de Pyrrhulina australis Eigenmann & Kennedy, 1903, o único Lebiasinidae da planície alagável do Alto Rio Paraná. Para isso, foram analisados 80 indivíduos, sendo 60 larvas e 20 juvenis, coletados entre os anos de 1992 e 2005, em vários ambientes (rios, canais e lagoas). De cada exemplar, foram obtidos dados morfométricos e merísticos e, posteriormente, o padrão de crescimento entre as variáveis morfométricas foi analisado. As larvas apresentaram grande concentração de pigmentos na região superior do intestino, da cabeça e ao redor da boca. A notocorda foi caracterizada por possuir um prolongamento que, posteriormente, diferenciou-se em um raio da nadadeira caudal. A seqüência de formação das nadadeiras foi: caudal, dorsal, anal, pélvica e peitoral. Em relação aos miômeros, observou-se que estes variaram de 23 a 32 (12-20 pré- e 10-16 pós-anal). A análise do crescimento revelou que o comprimento do focinho e o diâmetro do olho foram alométricos, enquanto a altura e o comprimento da cabeça, bem como a altura do corpo e a distância pré-peitoral apresentaram crescimento abrupto, evidenciando diferentes taxas de crescimento entre os períodos larval e juvenil. Esses resultados revelam que neste intervalo ocorre grande parte da metamorfose na espécie.

Este trabalho descreve o desenvolvimento inicial de Pyrrhulina australis Eigenmann & Kennedy, 1903, o único Lebiasinidae da planície alagável do Alto Rio Paraná. Para isso, foram analisados 80 indivíduos, sendo 60 larvas e 20 juvenis, coletados entre os anos de 1992 e 2005, em vários ambientes (rios, canais e lagoas). De cada exemplar, foram obtidos dados morfométricos e merísticos e, posteriormente, o padrão de crescimento entre as variáveis morfométricas foi analisado. As larvas apresentaram grande concentração de pigmentos na região superior do intestino, da cabeça e ao redor da boca. A notocorda foi caracterizada por possuir um prolongamento que, posteriormente, diferenciou-se em um raio da nadadeira caudal. A seqüência de formação das nadadeiras foi: caudal, dorsal, anal, pélvica e peitoral. Em relação aos miômeros, observou-se que estes variaram de 23 a 32 (12-20 pré- e 10-16 pós-anal). A análise do crescimento revelou que o comprimento do focinho e o diâmetro do olho foram alométricos, enquanto a altura e o comprimento da cabeça, bem como a altura do corpo e a distância pré-peitoral apresentaram crescimento abrupto, evidenciando diferentes taxas de crescimento entre os períodos larval e juvenil. Esses resultados revelam que neste intervalo ocorre grande parte da metamorfose na espécie. This work describes the initial development of Pyrrhulina australis Eigenmann & Kennedy, 1903, the only known Lebiasinidae of the upper Paraná River floodplain. Eighty specimens were analyzed, sixty larvae and twenty juveniles, collected between 1992 and 2005 in several areas (rivers, channels and ponds). From each specimen morphometric and meristic data were obtained and, subsequently, growth patterns were analyzed. Larvae presented greater pigment concentrations in the superior region of the intestine, head and around the mouth. Notochord is characterized by possessing a protrusion that later becomes part of the caudal fin. The fin formation sequence is: caudal, dorsal, anal, pelvic and pectoral. In relation to myomeres we observed that their numbers ranged from 23 to 32 (12-20 preanal and 10-16 postanal). Growth pattern analyses revealed that nose length and eye diameter were allometric, whereas head height and length, as well as body height and pre-pectoral distance were better represented by the piecewise model, revealing that most of the body metamorphosis occurs during the transitional breakpoint between the larval and juvenile periods.

With the objective to analyze the temporary distribution of Pachyurus bonariensis larvae and its relationship with some environmental variable, collections were carried in the Sinha Mariana bay, Mato Grosso State, between March/2000 and March/2004, at 4:00 p.m. and at 10:00 p.m. Simultaneously, water samples were obtained to determine temperature of the water, dissolved oxygen, pH and electric conductivity. The largest densities were verified between the months of October and January, suggesting to be this the main period of reproduction of the species. However, larvae in preflexion and flexion were also found in the months of winter, possibly associated to the favorable conditions for the reproduction. Individuals of all of the stages were present, thus it is probable that the whole life cycle happens inside of the bay. The density of larvae more developed in the surface is larger at night, while the initial larvae are found in the surface in both schedules, thus the degree of larval development influences in the distribution pattern of the species in the column of water.

With the objective to analyze the temporary distribution of Pachyurus bonariensis larvae and its relationship with some environmental variable, collections were carried in the Sinhá Mariana bay, Mato Grosso State, between March/2000 and March/2004, at 4:00 p.m. and at 10:00 p.m. Simultaneously, water samples were obtained to determine temperature of the water, dissolved oxygen, pH and electric conductivity. The largest densities were verified between the months of October and January, suggesting to be this the main period of reproduction of the species. However, larvae in preflexion and flexion were also found in the months of winter, possibly associated to the favorable conditions for the reproduction. Individuals of all of the stages were present, thus it is probable that the whole life cycle happens inside of the bay. The density of larvae more developed in the surface is larger at night, while the initial larvae are found in the surface in both schedules, thus the degree of larval development influences in the distribution pattern of the species in the column of water. Com o objetivo de analisar a distribuição temporal de larvas de Pachyurus bonariensis e sua relação com algumas variáveis ambientais, foram feitas coletas na baía Sinhá Mariana, Mato Grosso, entre março/2000 e março/2004, às 16 e 22h. Simultaneamente, amostras de água foram obtidas para determinar temperatura da água, oxigênio dissolvido, pH e condutividade elétrica. As maiores densidades foram verificadas entre os meses de outubro e janeiro, sugerindo ser este o principal período de reprodução da espécie. No entanto, larvas em estágio de pré-flexão e flexão também foram encontradas no inverno, possivelmente associadas às condições favoráveis para a reprodução. Indivíduos de todos os estágios estiveram presentes, ou seja, é provável que todo o ciclo de vida da espécie ocorra dentro da baía. A densidade de larvas mais desenvolvidas na superfície foi maior à noite, enquanto as larvas iniciais foram encontradas na superfície em ambos os horários, ou seja, o grau de desenvolvimento morfológico larval influencia no padrão de distribuição da espécie na coluna de água.

Made available in DSpace on 2013-08-12T18:43:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-01-01 Made available in DSpace on 2013-09-30T18:41:12Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-01-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T13:54:11Z No. of bitstreams: 0 Made available in DSpace on 2014-05-20T13:54:11Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-01-01 Aim: Studies on feeding of early life stages are very important to the understanding of the biology and trophic ecology of fish species. Therefore, the aim of this work is to describe the development of the digestive tube, and to characterize the diet of larvae and juveniles of Bryconamericus stramineus Eigenmann, 1908 of the upper Parana River floodplain; Methods: Larvae were obtained from, monthly samples during nychthemeral cycles with four-hour interval between samplings from February/91 to February/92, utilizing a conical-cylindrical plankton net; Results: At the preflexion stage, larvae at approximately 4.00 mm SL, showed a morphologically undifferentiated straight tube, with the anterior region more dilated. At the flexion stage a differentiation in the anterior region of the digestive tube occurs, with the intestine wall getting thicker (8.30 mm SL). The formation of pyloric caeca occurs at 9.00 mm SL. At the postflexion stage the first loop is formed at 9.25 mm SL and the second loop at about 10.00 mm SL. Bryconamericus stramineus consumed mainly cladocerans, also ingesting copepods, rotifers, nematodes, algae, insects and inorganic particles. Along the development, there was an increase in the number of food items and a diversification in the number of consumed taxa; Conclusions: Changes in the diet of B. stramineus larvae were not observed, being them zooplanktivores during all the initial development. However, an increase of large preys, such as insects larvae, was observed at the end of the larval period and in juveniles, suggesting a tendency towards invertivory. Larvae and juveniles preferentially fed during the night. Programa de Pos-graduacao em Zoologia, Instituto de Biociencias, Universidade Estadual Paulista - UNESP, Campus de Botucatu, Distrito de Rubiao Jr., s/n, CEP 18618-000, Botucatu, SP Programa de Pos-graduacao em Zoologia, Instituto de Biociencias, Universidade Estadual Paulista - UNESP, Campus de Botucatu, Distrito de Rubiao Jr., s/n, CEP 18618-000, Botucatu, SP

Oliveira, Edinbergh Caldas De, Bialetzki, Andréa, Assakawa, Luciana Fugimoto (2008): Morphological development of Hypophthalmus fimbriatus and H. marginatus post-yolk-sac larvae (Siluriformes: Pimelodidae). Zootaxa 1707: 37-48, DOI: 10.5281/zenodo.180930

Hypophthalmus marginatus (Fig. 3 a���f) Description of the larvae. A total of 66 larvae (14 preflexion, 49 flexion and 3 postflexion) with standard lengths between 3.0 and 13.1 mm were analyzed. The larvae of this species exhibit a relatively long body (12.4 to 16.7 % SL) and a head length varying from small to moderate (14.6 to 25 % SL) (Table 1). There is no trace of yolk. During the preflexion stage the mouth is open and terminal. The nostrils are single and become double at approximately 12.2 mm SL (postflexion). The barbles are formed: 2 mental pairs and 1 maxillary pair. They are longer and thinner compared to those of H. fimbriatus. The embryonic membrane (median fin fold) is hyaline and surrounds the body from the middle region of the dorsum to the abdominal portion and is totally absorbed at the end of the postflexion stage (13.1 mm SL). The eyes are rounded and pigmented with a diameter varying from 5.6 to 9.4 % HL, classifying it as small during it���s entire development (Table 1). The operculum is formed at about 12.2 mm SL. The intestine is short, and the position of the anal opening does not reach the middle portion of the body. Myomeres are evident until the flexion stage with a total number varying from 54 to 57 (13 to 15 pre- and 40 to 42 post-anal). Proportions of head depth (62.5 to 100 % HL), head width (54.8 to 100 %) and interorbital distance (33.5 to 54 % HL) decrease during development while snout length (25 to 54 % HL), pre-pectoral-fin length (17.9 to 26.% SL), pre-dorsal-fin length (39.9 to 44.7 % SL), and preanal-fin length (39.8 to 43.2 % SL) increase (Table 1). Pigmentation. As with the larvae of H. fimbriatus those of H. marginatus are also poorly pigmented. Some pigments can be observed dispersed along the body starting at 9 mm SL (postflexion). At about 10.8 mm SL they can also be barely visible on the upper region of the head. Fin development. The transparent notochord is visible and flexed at 4.3 mm SL giving support to the caudal-fin rays that appear at 4.5 mm SL (flexion) and are fully formed at 7.1 mm SL (flexion). At the beginning of the flexion stage, it is possible to see the pectoral fin bud in addition to the outline of the anal and dorsal fins. By the end of this stage (about 10.8 mm SL), all of the aforementioned rays are formed except the pectoral. Between the flexion and postflexion stages (about 12.5 mm SL), the pelvic fin bud appears, and the first rays are formed at about 13.1 mm SL. In the postflexion stage, the formation of the unpaired fins is completed including the segmentation of the rays. The numbers of fin rays in H. marginatus are pectoral: i+ 9, dorsal: i, 6���8, and anal: 61���62. Proportions of body. ANCOVA showed a significant relationship between head depth, snout length, interorbital distance, eye diameter and head width (all as a proportion of HL) (Fig. 4 a���e), and between head length, body depth and pre-pectoral-fin length. Pre-dorsal-fin length and pre-anal-fin length (all as a proportion of SL) (Fig. 5 a���e) also showed significant relationships. The variable pre-ventral-fin length was not analyzed due to the lack of data on H. marginatus. Only a few of the analyzed variables showed differences between the two species. Eye diameter is initially similar between the two species. It increases gradually but more so in H. fimbriatus (Fig. 4 d). Head width also differed between the two species, being slightly greater in H. marginatus (Fig. 4 e). The analysis showed significant differences between the two species for both body depth and pre-pectoral-fin length. Both were initially greater in H. marginatus, but became greater in H. fimbriatus at about 5.5 mm SL for body depth and 9.5 mm SL for pre-pectoral-fin length (Fig. 5 b���c)., Published as part of Oliveira, Edinbergh Caldas De, Bialetzki, Andr��a & Assakawa, Luciana Fugimoto, 2008, Morphological development of Hypophthalmus fimbriatus and H. marginatus post-yolk-sac larvae (Siluriformes: Pimelodidae), pp. 37-48 in Zootaxa 1707 on pages 41-44, DOI: 10.5281/zenodo.180930

Hypophthalmus fimbriatus (Fig. 2 a���f) Description of the larvae. Sixty-one larvae (18 preflexion, 22 flexion and 21 postflexion), with standard lengths between 12.7 and 13.1 mm, were analyzed. The larvae of this species exhibit a long body (12.4 to 19.8 % SL) while head lengths vary from small to moderate (16.1 to 25 % SL) (Table 1). There is no trace of yolk. In preflexion, the mouth is open and terminal during its entire development. The nostrils are single and become double at approximately 10.2 mm SL (postflexion). Barbles were formed: 2 mental pairs and 1 maxillary pair. They are shorter and thicker compared to those of H. marginatus. The embryonic membrane (median fin fold) is hyaline and surrounds the body from the middle region of the dorsum to the abdominal portion, become totally absorbed by the end of the postflexion stage (13 mm SL). The eyes are rounded and pigmented, with a diameter varying from 7.8 to 15.7 % HL, classifying it as small throughout development (Table 1). The operculum is formed at about 10.1 mm SL. The intestine is short, and the position of the anal opening does not reach the middle portion of the body. The myomeres are evident until the postflexion stage, and the total number varies from 54 to 58 (13 to 16 pre- and 40 to 44 postanal). Proportions of head depth (65.3 to 100 % HL), head width (53.3 to 92 % HL), and pre-ventral-fin length (34.8 to 36.6 % SL) decreased during development, while snout length (25 to 50 % HL), interorbital distance (26.3 to 50.3 % HL), pre-pectoral-fin length (17.2 to 23.3 % SL), pre-dorsal-fin length (36.6 to 41.9 % SL) and pre-anal-fin length (37.7 to 43 % SL) increased (Table 1). Pigmentation. The larvae of H. fimbriatus are poorly pigmented. The pigments are evident starting at 10.9 mm SL (postflexion) and are restricted to the upper region of the head. Fin development. The notochord, visible due to transparency, is flexed at 5.1 mm SL, giving support to the rays of the caudal fin that start to appear at 6.4 mm SL (flexion) and are formed at 7.6 mm SL (flexion). At the beginning of the flexion stage, it is possible to see the pectoral fin bud, in addition to the outline of the anal and dorsal fins that until the this stage (about 9.6 mm SL) showed the rays entirely formed. Between the flexion and postflexion stages (11 mm SL), the pelvic fin bud also appears; the first rays appear at approximately 11.9 mm SL. The formation of the unpaired fins is completed during the postflexion stage, including the segmentation of the rays. The numbers of fin rays in H. fimbriatus are pectoral: i, 8���10, dorsal: i, 8���9, and anal: 58���60., Published as part of Oliveira, Edinbergh Caldas De, Bialetzki, Andr��a & Assakawa, Luciana Fugimoto, 2008, Morphological development of Hypophthalmus fimbriatus and H. marginatus post-yolk-sac larvae (Siluriformes: Pimelodidae), pp. 37-48 in Zootaxa 1707 on pages 39-41, DOI: 10.5281/zenodo.180930

The aim of this study was to characterize the early development of Hoplias aff. malabaricus . The sampling was conducted during the period from November 1991 through February 1995, at 42 stations distributed in different environments of the upper Parana river floodplain, Brazil. The specimens were taken from limnetic and littoral regions. Specimens were separated according to their development in larval (preflexion, flexion and postflexion stages) and juvenile periods. Morphometric and meristic variables were analyzed in 269 larvae and 74 juveniles (standard length ranging from 6.17 mm to 49.12 mm). Larvae showed fusiform body and intense pigmentation, a long intestine, large eyes and terminal mouth. Number of myomeres ranged from 37 to 45 (23-28 pre and 11-18 post-anal). The juveniles presented a body shape similar to their adults. The numbers of fin rays were: pectoral, 12; pelvic, 7-9; dorsal, 13-15; and anal, 10-12. Analysis of the growth showed metamorphosis in the early development of this species.

The early development of Leporinus friderici (Bloch, 1794) is characterized in this research. Eggs and larvae were obtained from artificial spawning performed in Volta Grande hatchery (CEMIG), from February to March 1995. Juveniles were taken from samples of the Upper Paraná River Basin. Thirty eggs, 114 larvae and 21 juveniles were analyzed. Eggs are sphericals, transparents and non-adhesives, mean diameter 2.53 mm, perivitelline space 0.74 mm, mean yolk diameter 0.94 mm. Incubation time was 13h20min. at 27.6ºC. Larvae showed two pigments in frontal region, a long intestine reaching near the caudal fin, and pigments along the ventral margin of the body. Myomere number ranged from 35 to 37 O objetivo desse trabalho é caracterizar o desenvolvimento inicial de Leporinus friderici. Os ovos e larvas analisados foram obtidos através de desovas induzidas realizadas junto à estação de Piscicultura de Volta Grande (CEMIG), entre os meses de fevereiro e março de 1995. Os juvenis são provenientes de amostras coletadas na bacia do alto rio Paraná. Foram analisados 30 ovos, 114 larvas e 21 juvenis. Os ovos são esféricos, transparentes e não adesivos, com diâmetro médio de 2,53 mm, espaço perivitelino de 0,74 mm e diâmetro médio do vitelo de 0,94 mm. As larvas eclodem 13h20min. após a fertilização (27,6 ºC). Apresentam dois cromatóforos na região frontal, intestino alcançando a porção distal do corpo, uma linha de cromatóforos dendríticos ao longo da região ventral e número de miômeros totais variando de 35 a 37

The purpose of this paper was to investigate differentiation and insertion position of fins in relation to the vertebral column in adult and juvenile fish, as a way to facilitate larvae identification. To visualize the bone structure, a total of 423 individuals of 20 fish species were analysed. Every individual was submitted to dissection, clearing and staining techniques. The number vertebrae varied from 28 to 67. The insertion of fins in relation to the vertebrae varied: for pectoral fins, between the 1st and the 8th vertebrae, for pelvic fins, between the 6th and the 22nd, for dorsal fin, between the 12th and the 46th and anal fin, between the 12th and the 45th. Considering that the number of vertebrae in adults was related to the number of myomeres in larvae, we suggest that the number of vertebrae and the insertion of the fin in the vertebral column, along with other characters, may help in the identification of early life stages of fishes. O presente trabalho investigou a diferenciação do número de vértebras e discriminou a posição de inserção das nadadeiras em relação à coluna vertebral de peixes juvenis e adultos, a fim de fornecer subsídios à identificação de larvas. Foram analisados 423 indivíduos de 20 espécies, sendo que para a visualização das estruturas ósseas foram utilizados os métodos de diafanização e dissecção. A variação no número de vértebras foi de 28 a 67. As inserções das nadadeiras em relação às vértebras variaram: para peitoral, entre a 1ª e 8ª vértebras; para pélvica, entre a 6ª e 22ª; para dorsal entre a 12ª e 46ª e para anal, entre a 12ª e 45ª. Considerando que existe relação entre o número de vértebras encontrado nos adultos e o número de miômeros encontrado nas larvas, pode-se sugerir que o número de vértebras e posição das nadadeiras, juntamente com outros caracteres, auxiliarão na identificação dos estágios iniciais de desenvolvimento dos peixes.

The aim of the present study was to characterize the early development of Auchenipterus osteomystax (Ribeiro, 1918) (Osteichthyes, Auchenipteridae). Specimens were taken from plankton samples in the Upper Paraná river, Ivaí river, Upper Ivinhema river and Itaipu Reservoir. Seventy-four larvae and seven juveniles (with standard length ranging from 5.25 mm to 39.0 mm) were analyzed. Specimens were identified and separated according to their development and morphometric and meristic analyses were performed. The early development of A. osteomystax follows the pattern of other Siluriformes. However, individuals presented more pigmentation on the head and on fore part of the body. Number of myomeres ranged from 44 to 50 O objetivo deste trabalho é caracterizar o desenvolvimento inicial de Auchenipterus osteomystax (Ribeiro, 1918) (Osteichthyes, Auchenipteridae). O material analisado é proveniente de amostras coletadas no plâncton no alto rio Paraná, rio Ivaí, alto rio Ivinhema e reservatório de Itaipu. Foram analisadas 74 larvas e 7 juvenis, entre 5,25 mm e 39 mm de comprimento padrão. Os espécimes foram identificados e separados em diferentes estágios, e foram obtidas as variáveis morfométricas e merísticas. As larvas de A. osteomystax apresentam o desenvolvimento inicial semelhante ao de outros Siluriformes, no entanto são caracterizadas principalmente por apresentar um aglomerado de pigmentos na cabeça e na região anterior do corpo e número de miômeros variando de 44 a 50

The aim of this paper was to analyze initial development and temporal distribution of larvae and juveniles of Bryconamericus stramineus and their relationship with some environmental variables of Ressaco do Leopoldo in the Upper Paraná River floodplain. The samples were taken from February 1991 to February 1992. The larvae and the juveniles were identified and described according to the with its morphologic and meristic characteristics. The larvae presented scarce pigmentation, subterminal mouth, medium anal opening and myomeres varying 35-40 (16-21 pre and 17-22 postanal). The greater densities of larvae and juveniles were verified in December 1991 and November 1991, respectively, mainly during the night. The larvae density was only correlated with precipitation Este trabalho teve como objetivo caracterizar o desenvolvimento inicial e verificar a distribuição temporal de larvas e juvenis de Bryconamericus stramineus e a sua relação com algumas variáveis ambientais. O material foi obtido ao longo de ciclos nictemerais no Ressaco do Leopoldo, planície alagável do alto rio Paraná, entre fevereiro de 1991 e fevereiro de 1992. As larvas e juvenis foram identificados e descritos quanto às suas características morfológicas e merísticas, sendo que as larvas apresentaram pigmentação escassa, boca subterminal, abertura anal mediana e número de miômeros variando de 35 a 40 (16 a 21 pré e 17 a 22 pós-anal). As larvas e juvenis foram capturados em praticamente todo o período amostrado, com maiores abundâncias em dezembro e novembro, respectivamente, principalmente no período noturno. Relações entre as densidades e as variáveis ambientais foram significativas somente entre as larvas e a pluviosidade

Feeding aspects of Apareiodon affinis larvae and juveniles are described in this work. Samples collected by plankton net were taken from February, 1991 to February, 1992 in Ressaco do Leopoldo, Paraná River. The mouth is small and terminal in preflexion and flexion larvae and inferior at the end of this development period and in juveniles. The digestive tract is simple and straight in preflexion larvae, but different in those in postflexion. The diet was basically algae, characterizing this species as algivorous during all its development. The analysis of the digestibility did not show the preferential time of feeding of the different development stages. This was probably because of the sampling type utilized and because of the food consumed by the individuals Aspectos da alimentação de larvas e juvenis de Apareiodon affinis são descritos. As amostragens foram realizadas no Ressaco do Leopoldo, alto rio Paraná, entre fevereiro de 1991 e fevereiro de 1992, utilizando rede de plâncton. Nas larvas em pré-flexão e flexão, a boca é pequena e terminal, passando a inferior no estágio de pós-flexão e nos juvenis. O tubo digestivo é simples e reto nas larvas em pré-flexão e diferenciado naquelas em pós-flexão. A dieta foi constituída principalmente por algas, caracterizando essa espécie como algívora durante todo o seu desenvolvimento. A análise da digestibilidade não evidenciou o horário preferencial de alimentação dos difirentes estágios de desenvolvimento, provavelmente em função do tipo de amostragem utilizada e do alimento consumido pelos indivíduos

The aim of this study was to analyze some feeding treats of Bryconamericus aff. iheringii larvae, sampled in both the limnetic and littoral regions of the Piquiri River, in Santa Maria reservoir, between July and November 2001. The larvae presented sub-terminal mouth in larval period. The digestive tract differentiated in terms of stomach and intestine only in the postflexion larvae. The larvae fed mainly on algae and microcrustacea allowing to characterize them as planktivorous. The intense morphologic shift in the digestive tract in the postflexion larvae coincided with an increase in the abundance of algae in relation to animals items; however, in general, all the items had their occurrence increased. Analysis of the digestion stage suggested that preflexion larvae, possibly, fed themselves during the day, and those more developed, at dusk and night Este trabalho teve como objetivo analisar alguns aspectos da alimentação de larvas de Bryconamericus aff. iheringii, capturadas nos meses de julho e novembro de 2001, nas regiões limnética e litorânea do reservatório de Santa Maria, rio Piquiri, Estado do Paraná. As larvas apresentaram boca subterminal durante todo o seu desenvolvimento. O tubo digestório se diferenciou em estômago e intestino apenas no estágio de pós-flexão. As larvas consumiram, principalmente, algas e microcrustáceos, o que permitiu caracterizá-las como planctófagas. A intensa modificação morfológica no trato digestório nos indivíduos em pós-flexão coincidiu com o aumento na abundância de algas em relação aos itens de origem animal; porém, de forma geral, a ocorrência aumentou para todos os itens. A análise do grau de digestão dos itens alimentares sugeriu que indivíduos em pré-flexão alimentaram-se, possivelmente, durante o dia, e os mais desenvolvidos, durante o entardecer e no período noturno

Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:20:41Z No. of bitstreams: 0Bitstream added on 2014-05-27T14:44:53Z : No. of bitstreams: 1 2-s2.0-23444433624.pdf: 468642 bytes, checksum: 0d8183499fd8d35638d2ff901a89e2c6 (MD5) Made available in DSpace on 2014-05-27T11:20:41Z (GMT). No. of bitstreams: 0 Previous issue date: 2003-07-01 The aim of this paper was to analyze initial development and temporal distribution of larvae and juveniles of Bryconamericus stramineus and their relationship with some environmental variables of Ressaco do Leopoldo in the Upper Paraná River floodplain. The samples were taken from February 1991 to February 1992. The larvae and the juveniles were identified and described according to the with its morphologic and meristic characteristics. The larvae presented scarce pigmentation, subterminal mouth, medium anal opening and myomeres varying 35-40 (16-21 pre and IT-22 postanal). The greater densities of larvae and juveniles were verified in December 1991 and November 1991, respectively, mainly during the night. The larvae density was only correlated with precipitation. Departamento de Biologia Universidade Estadual de Maringá, Maringa Instituto de Biociências Universidade Estadual Paulista Campus de Botucatu, Distrito de Rubião Jr. s/n, 18618-000, Botucatu, São Paulo Núcleo de Pesquisas em Limnologia, Ictiologia e Aqüicultura Universidade Estadual de Maringá, Maringa Pós-graduação em Ecologia de Ambientes Aquáticos Continentais Universidade Estadual de Maringá, Av. Colombo, 5790, 87020-900, Maringa, Parana Centro de Engenharia e Ciências Exatas Universidade Estadual do Oeste do Paraná, Rua da Faculdade, 2550, 87030-900, Toledo, Paraná Instituto de Biociências Universidade Estadual Paulista Campus de Botucatu, Distrito de Rubião Jr. s/n, 18618-000, Botucatu, São Paulo

Spatial and temporal distribution of larvae and juveniles of trahira, Hoplias aff. malabaricus (Erythrinidae), and their relationship with environmental parameters in the Upper Paraná River floodplain were analyzed. Sampling of larvae and juveniles of H. aff. malabaricus has been conducted during the period from November 1991 through February 1995, with 42 sampling stations distributed in four sub-areas: Ivinhema I, Ivinhema II, Baía, and Paraná. During the same period, data were obtained for water temperature, dissolved oxygen, pH, electrical conductivity, river level, precipitation index, and photoperiod. The largest catches of larvae were in the Ivinhema I sub-area (47.06%), and of juveniles in the Paraná sub-area (54.55%). Larvae and juveniles were caught from October to February. Larvae were mainly collected at night and in all types of environments sampled (lotic, semi-lotic, and lentic). Principal Component Analysis of the environmental parameters and larval density showed that the largest catches were obtained in dry season months, with low values for temperature, electrical conductivity, river level, and photoperiod, and with high concentrations of dissolved oxygen and pH. This reproductive strategy may minimizes predation and maximizes food utilization, as it enables the fish to reach advanced developmental stages, while most other species are spawning. Analisou-se a distribuição espaço-temporal de larvas e juvenis de Hoplias aff. malabaricus (Erythrinidae) na planície de inundação do alto rio Paraná e suas relações com algumas variáveis ambientais, verificando-se os habitats preferenciais para a reprodução e desenvolvimento inicial. As amostragens foram divididas em quatro fases realizadas durante o período de novembro de 1991 a fevereiro de 1995, sendo estabelecidas 42 estações de coleta distribuídas em 4 subáreas (Ivinhema I, Ivinhema II, Baía e Paraná). As coletas foram realizadas na coluna de água e na vegetação aquática marginal. Durante o período foram obtidos dados de temperatura da água, oxigênio dissolvido, pH, condutividade elétrica, nível fluviométrico, índice pluviométrico e fotoperíodo. As maiores capturas de larvas foram verificadas na subárea Ivinhema I (47,06%) e, de juvenis, na subárea Paraná (54,55%). As larvas foram encontradas entre outubro e fevereiro em todas as subáreas, já os juvenis foram encontrados até abril. As larvas foram capturadas principalmente durante o período noturno em todos os tipos de ambientes amostrados (lótico, semilótico e lêntico). A Análise de Componentes Principais, aplicada entre as variáveis ambientais e a densidade de larvas, revelou que as maiores capturas são obtidas em meses em que predominam baixos valores de temperatura, condutividade elétrica, nível fluviométrico e fotoperíodo e elevadas concentrações de oxigênio dissolvido e de pH, ou seja, em meses de seca. Esta estratégia reprodutiva minimiza a predação e maximiza o aproveitamento alimentar, uma vez que lhe permite alcançar estágios avançados enquanto a maioria das espécies está desovando.

Analysis of drift of ichthyoplankton in two channels in the River Paraná, Brazil, were made. Sampling was undertaken from October 1995 to April 1996 during nychthemeral cycles. Water samples were collected to determine several environmental variables. Eggs densities largely differed to layers, times of day and months. In both the channels, highest occurrence of eggs was detected between January and March; greater concentrations at the bottom, during night. With regard to larvae, densities were significantly different in channels, times of days and months. Maximum occurrences were seen in the right channel, in both layers, with largest capture between January and March. Surface of the both channels presented highest density of larvae during night. Water temperature, electrical conductivity and flux velocity were different in the two channels, however, these variables and larvae density didn't showed correlations. This indicates that there was another possible factor, might be influencing the distribution of ichthyoplankton.Este trabalho teve por objetivo analisar a deriva do ictioplâncton em dois canais com diferentes condições de topografia e velocidade de fluxo, entre os estados do Paraná e Mato Grosso do Sul (Brasil). As amostragens foram realizadas no período de outubro de 1995 a abril de 1996, durante ciclos nictemerais. Amostras de água foram coletadas para determinação de algumas variáveis ambientais. A densidade de ovos diferiu significativamente entre os estratos, horários e meses; sendo que em ambos os canais, as maiores ocorrências de ovos foram verificadas entre janeiro e março, com maiores concentrações no fundo durante o período noturno. Com relação as larvas, as densidades diferiram entre os canais, horários e meses. As maiores ocorrências foram observas no canal direito, em ambos estratos, com maior período de captura entre janeiro e março. A superfície dos canais apresentou as maiores densidades de larvas durante o período noturno. A temperatura da água, condutividade elétrica e velocidade de fluxo foram diferentes entre os canais, entretanto, essas variáveis e a densidade de larvas não mostraram correlação, indicando que possivelmente outro fator, esteja influenciando a distribuição do ictioplâncton neste ambiente.

With the purpose of characterizing morphologicaly the larvae and juveniles of Apareiodon affinis (Steindachner, 1879) and to verify their temporal distribution monthly samples were taken at Leopoldo's Inlet, upper Parana River. The specimens were captured with a conic-cylindrical plankton net of mesh size 0,5mm from March 1991 to February 1992. Soon after identification, the specimens were separeted according to their development (prefle-xion, flexion, posflexion and juvenile) and then the moiphometric analyses were performed. The results showed that the larvae were captured from August 1991 to February 1992, with greatest densities in November 1991. The specimens occured in every timetable, however, larvae in pretlexion and flexion were captured during day time and, posflexion and juvenile, at night. According to series of morphological development, high body proportions variation were verifyed mainly in the head lenght, eye diameter and in height body. Moreover, the individuais showed little pigmentation and myomeres number changing between 39 to 42. The majority of morphometric characteristics have negative allometry with the cxception of head lenght with regard to standart lenght that have positive allometry.

Studies on the occurrence, temporal distribution and nychthemeral variation of Macrobrachium amazonicum (Heller, 1862) were undertaken in Leopoldo's Inlet, upper Parana River, Porto Rico, Parana, Brazil. Seventeen thousand and sixty specimens (11,786 larvae and 5,274 juveniles) were captured with a conicalcylindrical plankton net of mesh 0.5mm in monthly samples between February 1991 and February 1992. Results show that the greatest densities of larvae (301.83 larvae/10m3) and juveniles (168.8/10m3) of this species were caught in December 1991. Largest captures were made during the night. With regard to abiotic factors water temperature ranged from 20o to 30oC, pH ranged from 5.66 to 7.37 and electric conductivity ranged from 51.83 to 65.33µS/cm. Relationship between the density of larvae and juveniles and abiotic factors was calculated by the Principal Components Analysis (PCA) which revealed the influence of some limnological variables especially on the distribution of larvae.

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