Hippolyte obliquimanus é um pequeno camarão carídeo da família Hippolitydae. Vários registros na literatura reportaram a ocorrência de hermafroditismo neste grupo. Assim, o objetivo do presente trabalho foi determinar o sistema sexual de H. obliquimanus, testando a hipótese da presença de um sistema gonocórico ou hermafrodita (protândrico ou simultâneo). Os animais foram coletados manualmente a cada dois meses na Praia do Itaguá (Ubatuba/SP) de março/2005 a janeiro/2006. Os animais foram analisados em relação ao sexo e a morfometria quanto ao comprimento da carapaça, a largura máxima do própodo, ao comprimento do dáctilo do pereópodo 3 e ao comprimento do apêndice masculino. Foram realizados experimentos em laboratório para investigar a possível mudança de sexo. Um total de 674 espécimes foi coletado: 211 machos, 339 fêmeas não ovígeras e 124 fêmeas ovígeras. O comprimento da carapaça variou de 0,55 a 3,20 mm, com as fêmeas sendo significativamente maiores que os machos. A distribuição de tamanho foi unimodal, com poucos indivíduos nas maiores classes de tamanho. A razão sexual total desviou significantemente do esperado 1:1 em favor das fêmeas (0,46:1). Houve maior ocorrência de indivíduos no período outono-inverno (75%) que na primavera-verão. Entretanto a razão sexual e a porcentagem de fêmeas ovígeras/total de fêmeas foram praticamente iguais para ambos os períodos sazonais estudados. Observou-se que H. obliquimanus apresenta dimorfismo sexual com relação ao pereópodo 3, não apresenta cincinnuli no pleópodo 1 e não há redução do apêndice masculino nos machos maiores. Não houve mudança de sexo nos animais observados nos experimentos. Em síntese, conclui-se que este perfil denota indícios de uma população com reprodução contínua sazonal, em que as fêmeas são mais abundantes e atingem maiores tamanhos que os machos, os machos apresentam o apêndice masculino bem desenvolvido, não há indivíduos em transição na população. Portanto, a escassez de evidências suportando a protandria de H. obliquimanus permitiu caracterizar a espécie estudada como gonocórica. / Hippolyte obliquimanus is a small caridean shrimp of the Hippolitydae family. Several registers in the literature reported the occurrence of hermaphroditism in this group. Thus, the aim of the present work was to determine the sexual system of H. obliquimanus, testing the hypothesis of the presence of a gonochoric or hermaphroditic (protandric or simultaneous) system. The animals were collected by hand every two months in the Itaguá Beach (Ubatuba/SP) from March 2005 through January 2006. The animals were analyzed in relation to sex and morphometry based on the carapace length, the maximum propodus width, the dactyl length of the pereopod 3 and the masculine appendix length. Experiments in laboratory were accomplished to investigate the possibility of sex change. A total of 674 specimens was collected: 211 males, 339 non ovigerous females and 124 ovigerous females. The carapace length ranged from 0.55 through 3.20 mm, with females being significantly larger than males. The size distribution was unimodal, with few individuals in the larger size classes. The total sex ratio skewed significantly of the expected 1:1 in favour of the females (0.46:1). There was a higher occurrence of individuals in the period fall-winter (75%) than spring-summer. However the sex ratio and the percentage of ovigerous females/total females were practically equals to both seasonal periods studied. It was observed that H. obliquimanus presented sexual dimorphism in relation to the pereopod 3, it didn\'t present cincinnuli in the pleopod 1 and there wasn\'t reduction of the masculine appendix in the larger males. There wasn\'t sex change in the animals observed in the experiments. In synthesis, it was concluded that this profile denoted indications of a population with seasonal continuous reproduction, with females being more abundant and reaching larger sizes than males, males presenting the well developed masculine appendix, and there wasn\'t transitional individuals in the population. Therefore, the paucity of evidence supporting protandry in H. obliquimanus allowed to characterize this studied species as gonochoric.

Hippolyte obliquimanus é um pequeno camarão carídeo da família Hippolitydae. Vários registros na literatura reportaram a ocorrência de hermafroditismo neste grupo. Assim, o objetivo do presente trabalho foi determinar o sistema sexual de H. obliquimanus, testando a hipótese da presença de um sistema gonocórico ou hermafrodita (protândrico ou simultâneo). Os animais foram coletados manualmente a cada dois meses na Praia do Itaguá (Ubatuba/SP) de março/2005 a janeiro/2006. Os animais foram analisados em relação ao sexo e a morfometria quanto ao comprimento da carapaça, a largura máxima do própodo, ao comprimento do dáctilo do pereópodo 3 e ao comprimento do apêndice masculino. Foram realizados experimentos em laboratório para investigar a possível mudança de sexo. Um total de 674 espécimes foi coletado: 211 machos, 339 fêmeas não ovígeras e 124 fêmeas ovígeras. O comprimento da carapaça variou de 0,55 a 3,20 mm, com as fêmeas sendo significativamente maiores que os machos. A distribuição de tamanho foi unimodal, com poucos indivíduos nas maiores classes de tamanho. A razão sexual total desviou significantemente do esperado 1:1 em favor das fêmeas (0,46:1). Houve maior ocorrência de indivíduos no período outono-inverno (75%) que na primavera-verão. Entretanto a razão sexual e a porcentagem de fêmeas ovígeras/total de fêmeas foram praticamente iguais para ambos os períodos sazonais estudados. Observou-se que H. obliquimanus apresenta dimorfismo sexual com relação ao pereópodo 3, não apresenta cincinnuli no pleópodo 1 e não há redução do apêndice masculino nos machos maiores. Não houve mudança de sexo nos animais observados nos experimentos. Em síntese, conclui-se que este perfil denota indícios de uma população com reprodução contínua sazonal, em que as fêmeas são mais abundantes e atingem maiores tamanhos que os machos, os machos apresentam o apêndice masculino bem desenvolvido, não há indivíduos em transição na população. Portanto, a escassez de evidências suportando a protandria de H. obliquimanus permitiu caracterizar a espécie estudada como gonocórica. / Hippolyte obliquimanus is a small caridean shrimp of the Hippolitydae family. Several registers in the literature reported the occurrence of hermaphroditism in this group. Thus, the aim of the present work was to determine the sexual system of H. obliquimanus, testing the hypothesis of the presence of a gonochoric or hermaphroditic (protandric or simultaneous) system. The animals were collected by hand every two months in the Itaguá Beach (Ubatuba/SP) from March 2005 through January 2006. The animals were analyzed in relation to sex and morphometry based on the carapace length, the maximum propodus width, the dactyl length of the pereopod 3 and the masculine appendix length. Experiments in laboratory were accomplished to investigate the possibility of sex change. A total of 674 specimens was collected: 211 males, 339 non ovigerous females and 124 ovigerous females. The carapace length ranged from 0.55 through 3.20 mm, with females being significantly larger than males. The size distribution was unimodal, with few individuals in the larger size classes. The total sex ratio skewed significantly of the expected 1:1 in favour of the females (0.46:1). There was a higher occurrence of individuals in the period fall-winter (75%) than spring-summer. However the sex ratio and the percentage of ovigerous females/total females were practically equals to both seasonal periods studied. It was observed that H. obliquimanus presented sexual dimorphism in relation to the pereopod 3, it didn\'t present cincinnuli in the pleopod 1 and there wasn\'t reduction of the masculine appendix in the larger males. There wasn\'t sex change in the animals observed in the experiments. In synthesis, it was concluded that this profile denoted indications of a population with seasonal continuous reproduction, with females being more abundant and reaching larger sizes than males, males presenting the well developed masculine appendix, and there wasn\'t transitional individuals in the population. Therefore, the paucity of evidence supporting protandry in H. obliquimanus allowed to characterize this studied species as gonochoric.

A mutualistic symbiosis exists between the alga Sargassum spp. and two shrimp species, L. tenuicornis and L. fucorum. But little is known about how the shrimp locate their host alga. Both visual and chemical cues are potentially available. Visual cues would be presumably restricted at night but chemical cues are potentially available continuously. Additionally, a previous study has looked at both cue variables with results that are mixed. This current research elaborates on the previous study in an attempt to fully understand Sargassum shrimp chemoreception. A y-maze and four-chambered apparatus were used to test if the shrimp were able to detect Sargassum cues, conspecific cues, and Dimethylsulfoniopropionate (DMSP) cues. Neither shrimp species showed a strong directional response to any of the chemical cues, but the Sargassum and DMSP cues did cause more shrimp to exhibit searching behavior. Additionally, several differences in response between male and female shrimp were found for each cue. A weaker dilution of DMSP was tested in an attempt to determine sensitivity of L. fucorum shrimp to the chemical cue. This weaker dilution also caused L. fucorum to exhibit searching behavior, but the sensitivity to the cue was not found and further research is needed to fully answer this question. These results show the shrimp are able to detect chemical cues in their environment and help determine more accurately the role of chemoreception in initiating and maintaining this shrimp/algal association. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2019. / FAU Electronic Theses and Dissertations Collection