First island species of Hyalella (Amphipoda, Hyalellidae) from Florianpolis, state of Santa Catarina, Southern Brazil.

The Hyalella comprises a group of freshwater amphipods endemic to the Americas. In Brazil, the greatest diversity of species known so far is concentrated in the state of Rio Grande do Sul, but recently discoveries were made in the neighboring state of Santa Catarina. The present work describes the first island species of the genus Hyalella in Brazil and the fifth with occurrence in the state of Santa Catarina. The species was found in streams of two watersheds, located at the Monumento Natural Municipal da Lagoa do Peri, an important environmental protection area on the island of Florianpolis, Southern Brazil. Hyalella insulae n. sp. shows the following characters: inner face of propodus of gnathopod 1 with 7 serrate setae, gnathopod 2 with propodus ovate, peduncle of uropod 3 with 10 cuspidate setae, telson rectangular, wider than long, with 6 cuspidate setae and 2 plumose setae laterally close to each distal seta. H. insulae n. sp. differs from the other species with occurrence in Santa Catarina, H. catarinensis, H. rioantensis, H. sambaqui and H. lagoana, mostly concerning to the number and shape of setae of the gnathopods, uropods and telson. A comparison was also made with species from the neighboring states, Rio Grande do Sul and Paran. The description of H. insulae n. sp. in the present study contributes to increasing the knowledge of the Hyalella diversity in the state of Santa Catarina, little known so far.

A new species of freshwater amphipod (Crustacea, Peracarida, Hyalellidae) from Southern Brazil.

The freshwater amphipod of the genus Hyalella is typical from continental American waters and shows high levels of endemicity and Brazil has the second largest diversity. A new species is described here, Hyalella longipropodus n. sp. that occurs in a spring of southern Brazil in the municipality of Palmeira das Misses, in the northwestern region of state of Rio Grande do Sul, southern Brasil. Hyalella longipropodus n. sp. shows the following character states: antenna 2 more than half body length, gnathopod 2 propodus elongated, uropod 1 inner ramus of male without apical curved setae, uropod 3 peduncle with seven strong distal setae with accessory setae, ramus of uropod 3 with ten cuspidate setae with accessory setae. Hyalella longipropodus n. sp. occurs in sympatry with H. gauchensis, but these differ especially in the size and shape of gnathopod 2, the presence of curved setae on uropod 1 in H. gauchensis and the absence in H. longipropodus n. sp., antenna length (longer in H. longipropodus n. sp.) and number of cuspidate setae on uropods 1, 2, and 3. Besides the morphological differences, H. longipropodus n. sp. presented genetic differences always above 19% for the COI gene and 29 % for the 16S rRNA gene, when compared with other species found in the northwestern region of the state of Rio Grande do Sul, showing that it is really a species not yet described by science.

Induction of ovarian growth in Aegla platensis (Crustacea, Aeglidae) by means of neuroregulators incorporated to food

The freshwater crab Aegla platensis was used as a model to induce ovarian growth by adding different neuroregulators to a pellet food formulation. Added compounds were the dopaminergic inhibitor spiperone or the enkephalinergic inhibitor naloxone, both of them at a dose of 10-8 mol/animal. Animals were fed on the enriched pellets twice a week. After 7 wk, the gonadosomatic index (GI) was calculated as (gonad fresh weight / body fresh weight) x 100. GI significantly increased only for those females fed on spiperone pellets, compared to a control group receiving pellets with no compound added. During the assayed period, spiperone would be reverting the arrest exerted by dopamine on the neuroendocrine stimulation of ovarian growth. On the other hand, for both spiperone and naloxone a higher GI was correlated to a higher lipid content of both gonads and/or hepatopancreas, suggesting an increased energetic demand in accordance with an active investment in reproduction. Rev. Biol. Trop. 56 (3): 1201-1207. Epub 2008 September 30.

Se utilizó al anomuro de agua dulce Aegla platensis como modelo para inducir el crecimiento ovárico mediante el agregado de diferentes neuroreguladores a una formulación de alimento pelleteado. Los compuestos agregados fueron el inhibidor dopaminergico spiperona ó el inhibidor encefalinérgico naloxone, ambos a una dosis de 10-8 moles/animal. Los animales fueron alimentados dos veces a la semana con pellets enriquecidos con alguno de los neuroreguladores. Luego de 7 semanas, se calculó el índice gonadomático (IG) como (peso gonadal fresco/ peso corporal fresco) x 100. El IG mostró un incremento significativamente sólo en aquellas hembras alimentadas con pellets enriquecidos con spiperona, en comparación con un grupo control que recibió pellets sin agregado alguno. Durante el período ensayado, la spiperona estaría revirtiendo el arresto ejercido por la dopamina sobre la estimulación neuroendocrina del crecimiento ovárico. Por otro lado, para ambos grupos experimentales (spiperona y naloxone), un mayor valor de IG estuvo correlacionado a un mayor incremento del contenido de lípidos tanto en gonadas como en hepatopáncreas, sugiriendo una demanda energética incrementada en relación con una activa inversión en reproducción.

Gonad development in females of fiddler crab Uca rapax (Crustacea, Brachyura, Ocypodidae) using macro and microscopic techniques

The morphology of the ovaries in Uca rapax (Smith, 1870) was described based on macroscopic and microscopic analysis. Females were collected in Itamambuca mangrove, Ubatuba, state of São Paulo, Brazil. In the laboratory, 18 females had their ovaries removed and prepared for histology. Each gonad developmental stage was previously determined based on external and macroscopic morphology and afterwards each stage was microscopically described. The ovaries of U. rapax showed a pronounced macroscopic differentiation in size and coloration with the maturation of the gonad, with six ovarian developmental stages: immature, rudimentary, developing, developed, advanced and spent. During the vitellogenesis, the amount of oocytes in secondary stage increases in the ovary, resulting in a change in coloration of the gonad. Oogonias, primary oocytes, secondary oocytes and follicular cells were histologically described and measured. In females ovaries of U. rapax the modifications observed in the oocytes during the process of gonad maturation are similar to descriptions of gonads of other females of brachyuran crustaceans. The similarities are specially found in the morphological changes in the reproductive cells, and also in the presence and arrange of follicle cells during the process of ovary maturation. When external morphological characteristics of the gonads were compared to histological descriptions, it was possible to observe modifications that characterize the process in different developmental stages throughout the ovarian cycle and, consequently, the macroscopic classification of gonad stages agree with the modifications of the reproductive cells.

A morfologia dos ovários de Uca rapax foi descrita baseada nas análises macroscópica e microscópica. As fêmeas foram coletadas no manguezal de Itamambuca, Ubatuba, Estado de São Paulo, Brasil. No laboratório, os ovários de 18 fêmeas foram retirados e preparados para histologia. Os estágios gonadais foram caracterizados previamente por meio de análises da morfologia externa e macroscopia e posteriormente cada estágio foi descrito microscopicamente. Os ovários das fêmeas de U. rapax apresentaram uma diferenciação macroscópica pronunciada no tamanho e coloração durante o processo de maturação, sendo caracterizados seis estágios de desenvolvimento ovariano: imaturo, rudimentar, em desenvolvimento, desenvolvido, avançado e esgotado. Microscopicamente, estes estágios diferiram quanto ao tamanho, cor e proporção de oogônias e oócitos presentes. Na análise histológica, oogônias, oócitos primários e secundários e células foliculares foram descritos e mensurados. As modificações observadas nos oócitos durante o processo de maturação dos ovários das fêmeas de U. rapax são similares às descrições de gônadas de outras fêmeas de braquiúros. As semelhanças foram especialmente observadas nas mudanças morfológicas das células reprodutivas e, também no arranjo das células foliculares durante o processo de maturação ovariana. Quando as características morfológicas externas das gônadas foram comparadas com as descrições histológicas, foi possível observar modificações que caracterizam o processo em diferentes estágios de desenvolvimento do ciclo ovariano e conseqüentemente, a classificação macroscópica das gônadas coincide com as modificações nas células reprodutivas.

Gonad development in females of fiddler crab Uca rapax (Crustacea, Brachyura, Ocypodidae) using macro and microscopic techniques

The morphology of the ovaries in Uca rapax (Smith, 1870) was described based on macroscopic and microscopic analysis. Females were collected in Itamambuca mangrove, Ubatuba, state of São Paulo, Brazil. In the laboratory, 18 females had their ovaries removed and prepared for histology. Each gonad developmental stage was previously determined based on external and macroscopic morphology and afterwards each stage was microscopically described. The ovaries of U. rapax showed a pronounced macroscopic differentiation in size and coloration with the maturation of the gonad, with six ovarian developmental stages: immature, rudimentary, developing, developed, advanced and spent. During the vitellogenesis, the amount of oocytes in secondary stage increases in the ovary, resulting in a change in coloration of the gonad. Oogonias, primary oocytes, secondary oocytes and follicular cells were histologically described and measured. In female’s ovaries of U. rapax the modifications observed in the oocytes during the process of gonad maturation are similar to descriptions of gonads of other females of brachyuran crustaceans. The similarities are specially found in the morphological changes in the reproductive cells, and also in the presence and arrange of follicle cells during the process of ovary maturation. When external morphological characteristics of the gonads were compared to histological descriptions, it was possible to observe modifications that characterize the process in different developmental stages throughout the ovarian cycle and, consequently, the macroscopic classification of gonad stages agree with the modifications of the reproductive cells.

A morfologia dos ovários de Uca rapax foi descrita baseada nas análises macroscópica e microscópica. As fêmeas foram coletadas no manguezal de Itamambuca, Ubatuba, Estado de São Paulo, Brasil. No laboratório, os ovários de 18 fêmeas foram retirados e preparados para histologia. Os estágios gonadais foram caracterizados previamente por meio de análises da morfologia externa e macroscopia e posteriormente cada estágio foi descrito microscopicamente. Os ovários das fêmeas de U. rapax apresentaram uma diferenciação macroscópica pronunciada no tamanho e coloração durante o processo de maturação, sendo caracterizados seis estágios de desenvolvimento ovariano: imaturo, rudimentar, em desenvolvimento, desenvolvido, avançado e esgotado. Microscopicamente, estes estágios diferiram quanto ao tamanho, cor e proporção de oogônias e oócitos presentes. Na análise histológica, oogônias, oócitos primários e secundários e células foliculares foram descritos e mensurados. As modificações observadas nos oócitos durante o processo de maturação dos ovários das fêmeas de U. rapax são similares às descrições de gônadas de outras fêmeas de braquiúros. As semelhanças foram especialmente observadas nas mudanças morfológicas das células reprodutivas e, também no arranjo das células foliculares durante o processo de maturação ovariana. Quando as características morfológicas externas das gônadas foram comparadas com as descrições histológicas, foi possível observar modificações que caracterizam o processo em diferentes estágios de desenvolvimento do ciclo ovariano e conseqüentemente, a classificação macroscópica das gônadas coincide com as modificações nas células reprodutivas.

Ecologia populacional de Aegla franciscana (Crustacea, Decapoda, Anomura) em São Francisco de Paula, RS, Brasil

The aim of this research was to characterize population aspects of Aegla franciscana Buckup & Rossi, 1977, where the size-frequency distribution, sex ratio, recruitment, reproductive period (frequency of ovigerous females) and fecundity were evaluated. The samples were performed seasonally (February, June, August and October 2003) at river Rolante, Rio dos Sinos basin, São Francisco de Paula city, RS. The animals were collected with nets, measured and returned to the stream. A total of 1,322 individuals was obtained, among which 567 males, 579 females and 176 unsexed animals. The animals were bracketed in size classes for cephalothorax length (CL), and bimodal distribution was observed. Male sizes ranged from 3.86 mm to 22.09 mm and females from 4.06 mm to 22.48 mm. The males showed a larger median size (10.36 mm) than females (9.89 mm). The sex ratio obtained was close to 1:1 (chi2 = 0.03; p>0.05). Sex ratio in the size classes showed an anomalous pattern, with a higher frequency of females in the intermediate size classes and males in the superior classes. This may be related to a greater energy requirement for reproduction in females, thus delaying growth. The highest recruitment pulse occurred in summer and autumn as a consequence of high reproductive activity during winter. Ovigerous females produced 123.3 ± 47.8 eggs (mean ± standard deviation). A correlation between cephalothorax length of ovigerous females and number of eggs (r = 0.81) was observed.

A pesquisa teve como objetivos caracterizar aspectos populacionais de Aegla franciscana Buckup & Rossi, 1977 que ocorre em corpos d'água do planalto sul-rio-grandense, onde foram analisados a distribuição de freqüência em classes de tamanho, a proporção sexual, o período reprodutivo através da freqüência de fêmeas ovígeras, o recrutamento e a fecundidade da espécie. As amostragens foram realizadas sazonalmente, no arroio Rolante, município de São Francisco de Paula, RS. Os eglídeos foram coletados com puçás, medidos e devolvidos ao arroio. Foram amostrados 1.322 exemplares, sendo 567 machos, 579 fêmeas e 176 animais com sexo indefinido. Machos e fêmeas foram agrupados em classes de comprimento do cefalotórax (CC), onde foi observada distribuição bimodal. A amplitude do comprimento do cefalotórax dos machos variou de 3,86 mm a 22,09 mm e o das fêmeas de 4,06 mm a 22,48 mm, sendo que os machos apresentaram tamanho mediano (10,36 mm) superior ao das fêmeas (9,89 mm). A proporção sexual foi de 1:1 (chi2 = 0,03; p>0,05). Na análise da proporção sexual, por classes de tamanho, observou-se que os machos são mais freqüentes nas classes superiores e as fêmeas nas classes intermediárias. O primeiro registro do surgimento de juvenis na população ocorreu no verão e de fêmeas ovígeras no outono, estas ocorrendo mais freqüentemente no inverno. As fêmeas ovígeras produzem em média 123,3 ± 47,8 ovos; observou-se correlação entre o comprimento do cefalotórax das fêmeas ovígeras e o número de ovos (r = 0,81).

Ecologia populacional de Aegla franciscana (Crustacea, Decapoda, Anomura) em São Francisco de Paula, RS, Brasil

The aim of this research was to characterize population aspects of Aegla franciscana Buckup & Rossi, 1977, where the size-frequency distribution, sex ratio, recruitment, reproductive period (frequency of ovigerous females) and fecundity were evaluated. The samples were performed seasonally (February, June, August and October 2003) at river Rolante, Rio dos Sinos basin, São Francisco de Paula city, RS. The animals were collected with nets, measured and returned to the stream. A total of 1,322 individuals was obtained, among which 567 males, 579 females and 176 unsexed animals. The animals were bracketed in size classes for cephalothorax length (CL), and bimodal distribution was observed. Male sizes ranged from 3.86 mm to 22.09 mm and females from 4.06 mm to 22.48 mm. The males showed a larger median size (10.36 mm) than females (9.89 mm). The sex ratio obtained was close to 1:1 (chi2 = 0.03; p>0.05). Sex ratio in the size classes showed an anomalous pattern, with a higher frequency of females in the intermediate size classes and males in the superior classes. This may be related to a greater energy requirement for reproduction in females, thus delaying growth. The highest recruitment pulse occurred in summer and autumn as a consequence of high reproductive activity during winter. Ovigerous females produced 123.3 ± 47.8 eggs (mean ± standard deviation). A correlation between cephalothorax length of ovigerous females and number of eggs (r = 0.81) was observed.

A pesquisa teve como objetivos caracterizar aspectos populacionais de Aegla franciscana Buckup & Rossi, 1977 que ocorre em corpos d'água do planalto sul-rio-grandense, onde foram analisados a distribuição de freqüência em classes de tamanho, a proporção sexual, o período reprodutivo através da freqüência de fêmeas ovígeras, o recrutamento e a fecundidade da espécie. As amostragens foram realizadas sazonalmente, no arroio Rolante, município de São Francisco de Paula, RS. Os eglídeos foram coletados com puçás, medidos e devolvidos ao arroio. Foram amostrados 1.322 exemplares, sendo 567 machos, 579 fêmeas e 176 animais com sexo indefinido. Machos e fêmeas foram agrupados em classes de comprimento do cefalotórax (CC), onde foi observada distribuição bimodal. A amplitude do comprimento do cefalotórax dos machos variou de 3,86 mm a 22,09 mm e o das fêmeas de 4,06 mm a 22,48 mm, sendo que os machos apresentaram tamanho mediano (10,36 mm) superior ao das fêmeas (9,89 mm). A proporção sexual foi de 1:1 (chi2 = 0,03; p>0,05). Na análise da proporção sexual, por classes de tamanho, observou-se que os machos são mais freqüentes nas classes superiores e as fêmeas nas classes intermediárias. O primeiro registro do surgimento de juvenis na população ocorreu no verão e de fêmeas ovígeras no outono, estas ocorrendo mais freqüentemente no inverno. As fêmeas ovígeras produzem em média 123,3 ± 47,8 ovos; observou-se correlação entre o comprimento do cefalotórax das fêmeas ovígeras e o número de ovos (r = 0,81).