Morphology of the early larval stages of Lysmata ankeri Rhyne & Lin, 2006 and Lysmata bahia Rhyne & Lin, 2006 (Caridea: Lysmatidae) and a review of the larval morphology of the early Lysmata stages.

The early larval stages of the shrimps Lysmata ankeri and L. bahia were described, illustrated, and compared among other Lysmata species, providing important information on post-embryonic development and insights into its evolutionary history. Ovigerous specimens of L. ankeri and L. bahia were sampled from southeastern and northeastern Brazilian coast, respectively. For L. ankeri and L. bahia, five and three larval stages were obtained, respectively. Unique features were observed for L. ankeri and L. bahia larvae, and some characteristics may differ only for L. ankeri and L. bahia, which were not observed in the other species analyzed, such as: presence of a pair of simple setae on the third pleonal somite in zoea I and number of setae on the uropod exopod greater than 11. Moreover, several other features are similar between species from the diferent clades of the Lysmata-Exhippolysmata complex, making it possible to identify the early stages of Lysmata larvae. However, future studies will be essential to confirm or not the existence of some phylogenetic patterns and their relevance and other larval characters for better understanding the evolutionary history of this group.

New Insights into the Life-history Traits of the Night Shrimp Processa hemphilli (Caridea: Processidae) in the Western Atlantic.

We analyzed sexual dimorphism, sex ratio, relative growth, morphological sexual maturity, fecundity, embryo volume, and reproductive output of a population of the night shrimp Processa hemphilli from the Southeast coast of Brazil. Sampling was seasonally conducted, from June 2016 to April 2019 in Ubatuba, São Paulo. Our results showed the presence of sexual dimorphism in the body size, with females being larger than males. In addition, there was no difference in the overall sex ratio. However, it was possible to observe a skewed sex ratio to males in the smaller size classes, whereas females were more abundant in the larger size classes. The estimated carapace length at the onset of morphological sexual maturity of females and males was 3.6 mm and 3.2 mm, respectively. The mean fecundity of females was 285 ± 142 embryos (mean ± SD) embryos and was positively correlated with the carapace length. The embryo volume differed between the developmental stages with a constant increase in volume throughout the development between stages I and III. The mean reproductive output of females was 52.4%. Our results suggest that P. hemphilli have a pure search mating system, show sex allocation in the growth of body structures, and that females have high reproductive investment. All of these results represent the first insights into the life-history traits of the species in the western Atlantic and contribute to the knowledge about processid species.

New Insights into the Male Morphotypes of the Amphidromous Shrimp Macrobrachium olfersii (Weigmann, 1836) (Caridea: Palaemonidae) and a Discussion on Social Dominance Hierarchies.

Male morphotypes in a population may lead to the development of social dominance hierarchies in crustacean species. Currently, Macrobrachium is the decapod crustacean genus with the largest record of species that present the development of hierarchies. Macrobrachium olfersii has morphological characteristics that indicate the presence of male social dominance within its populations. Thus, the present study tested the hypothesis of the occurrence of male morphotypes in M. olfersii through morphometric and morphological analysis of the chelipeds. Sampling was carried out from March 2018 to October 2021 in seven points along the Jequitinhonha River, Northeast Brazil. A total of 264 males were collected with carapace length (CL) ranging from 4.01 to 23.70 mm. Morphological sexual maturity size was estimated at 8.95 mm CL. The morphometric and morphological analysis confirmed the presence of three adult male morphotypes: M1, M2, and M3. The characterization of the different morphotypes was mainly due to the variation in size, shape, and morphology of the largest cheliped of the second pair of pereopods. Most morphometric relationships differed significantly (p < 0.01) among the three morphotypes, mainly between M3 against M1 and M2. The variation in the propodus shape was also evident. This trait and the angulation of the spines differed significantly between morphotypes (p < 0.01), with the propodus of morphotype M3 being more robust and carrying a greater number of spines than the others. The occurrence of social dominance and the exaggerated development of a cheliped (weapon) can be advantageous for dominant individuals when they need to compete for resources. This morphological trait can provide these individuals with advantages during fights and guarantee access to the best resources, whether they are shelter, food, or sexual partners. Our results add new information to the biology of M. olfersii, as well as the genus Macrobrachium, and the occurrence of social dominance in species of this group. In addition, by describing these morphotypes in detail, using a set of complementary morphological and morphometric techniques, it is possible to access the differential morphology along the M. olfersii males, as well as confirm a life history trait found in several Macrobrachium species.

Early larval development of the rock shrimps Sicyonia dorsalis Kingsley, 1878 and S. typica (Boeck, 1864) (Dendrobranchiata) with remarks of larval morphology of Sicyoniidae Ortmann, 1898 / Desenvolvimento larval inicial dos camarões-pedra Sicyonia dorsalis Kingsley, 1878 e S. typica (Boeck, 1864) (Dendrobranchiata) com observações sobre a morfologia larval de Sicyoniidae Ortmann, 1898

Abstract The aim of this study was to describe and illustrate the early larval stages, i.e., the complete naupliar development and the first protozoea (PZI) of Sicyonia dorsalis and S. typica obtained under laboratory conditions. We also provide remarks from a comparative analysis of the morphology of these stages among representatives of the genus and furnish morphological characteristics to distinguish them from another penaeoidean in the plankton. Our results indicate that the naupliar development of Sicyonia is composed of five stages (NI to NV). No differences were found in the morphology of the naupliar and PZI stages of the two studied species, even though they are considered phylogenetically distant into the genus. We suspect that morphological differences arise later during ontogenetic development. The comparisons with larval descriptions of congeners revealed that naupliar stages and PZI were very similar, nevertheless, some morphological differences were observed. As illustrated here, there is a clear need of new descriptions of the studied group and generalizations and conclusions of larval morphology patterns at this point need to be made with caution, because data of a still insufficient number of species is available.

Resumo O objetivo deste estudo foi descrever e ilustrar os estágios larvais iniciais, ou seja, o desenvolvimento naupliar completo e a primeira protozoea (PZI) de Sicyonia dorsalis e S. typica obtidos em laboratório. Também fornecemos observações a partir de uma análise comparativa da morfologia desses estágios entre representantes do gênero e as características morfológicas para distingui-los de outros Penaeoidea no plâncton. Nossos resultados indicam que o desenvolvimento naupliar de Sicyonia é composto por cinco estágios (NI a NV). Não foram encontradas diferenças na morfologia dos estágios naupliares e PZI das duas espécies estudadas, apesar de serem consideradas filogeneticamente distantes dentro do gênero. Nossa hipótese é que as diferenças morfológicas surgem mais tarde durante o desenvolvimento ontogenético. As comparações com as descrições larvais de congêneres revelaram que os estágios naupliares e PZI são muito semelhantes, no entanto, algumas diferenças morfológicas foram observadas. Conforme ilustrado aqui, há uma clara necessidade de novas descrições do grupo estudado e generalizações e conclusões de padrões na morfologia larval neste momento precisam ser feitas com cautela, pois dados de um número ainda insuficiente de espécies estão disponíveis.

Morphology of the early larval stages of Lysmata lipkei Okuno amp; Fiedler, 2010 (Caridea: Lysmatidae): an invasive shrimp in the Western Atlantic.

Considering the importance of establishing different approaches to the early detection of invasive species, the present study aimed to describe and illustrate the morphology of the early larval stages of the shrimp Lysmata lipkei, an invasive species in the Western Atlantic. Additionally, we did a morphological comparison and a review of the other Lysmata species from the Western Atlantic Ocean with a known larvae description. The larvae used in this study were obtained by the maintenance, under laboratory conditions, of ovigerous hermaphrodites of L. lipkei, collected in the wild. Then, larvae were dissected under a stereo microscope and illustrated using a microscope equipped with a camera lucida. The first three larval stages (zoeae) of L. lipkei were illustrated, described, and compared to other species of Lysmata previously described of the Western Atlantic. Some features of the larval morphology of L. lipkei are very similar when compared to other Lysmata species with previous larval descriptions, such as a rostrum long and simple, the eyes stalked with a long peduncle from the second zoeae, one pterygostomian spine and several denticles along the anterior ventral margin of the carapace, similarities in the segmentation of the maxillipeds, and the presence of dorsolateral spines on the posterior margin of the 5th pleomere, among other features. Also, unique features were observed for L. lipkei, such as differences in the setation of some structures, including the antennule, antenna, maxillule, and maxillipeds. Using the morphological descriptions, we expect to identify species from the plankton, especially invaders, that might be present in the Western Atlantic, as well as assist in several areas in which the larval morphology is relevant.

Spatial and temporal distribution and abundance of two species of Persephona (Decapoda: Brachyura: Leucosiidae) on the southern coast of the state of São Paulo, Brazil / Distribuição espacial e temporal e abundância de duas espécies do gênero Persephona (Decapoda: Brachyura: Leucosiidae) no litoral sul do estado de São Paulo, Brasil

Abstract: Crabs of the genus Persephona are intensely captured in shrimp fisheries as bycatch in the Cananéia region off the coast of the state of São Paulo, Brazil. The analysis of the spatial and temporal distribution of Persephona punctata and Persephona mediterranea could provide information about variation in the abundance of these species, as well as the environmental variables affecting their distribution and the existence of a possible habitat partitioning. Using a shrimp fishery boat equipped with double-rig nets, crabs were monthly captured from July 2012 to June 2014 in seven sites: four in the coastal area adjacent to the Cananéia region and three in the Mar Pequeno estuarine area. The abundances of both species were compared according to spatial (among sites) and temporal (years and seasons) scale distribution. A total of 396 individuals of P. punctata and 64 of P. mediterranea were captured. The abundance of both species was higher in the second sampling year (July 2013-June 2014) and in coastal areas; only one individual of each species was captured in the estuarine area due to the low salinity at this location (approximately 27.7‰). The temperature was the environmental variable that most affected the distribution of both species, which was more abundant in warmer periods. The temporal variation in abundance was modulated by temperature, while salinity modulated the spatial distribution of P. punctata and P. mediterranea. The spatial-temporal distribution of both species differered in Cananéia, pointing to a similar use of the environment's resources.

Resumo: Os caranguejos Persephona são intensamente capturados na pesca do camarão como fauna acompanhante, inclusive na região de Cananéia no litoral do estado de São Paulo, no Brasil. A avaliação da distribuição espaço-temporal pode, consequentemente, fornecer informações sobre variações na abundância de Persephona punctata e Persephona mediterranea, bem como as variáveis ambientais que afetam suas distribuições e uma possível partilha de habitat desses congêneres. Com um barco de pesca de camarão equipado com redes de arrasto duplo, os indivíduos foram coletados mensalmente de julho de 2012 a junho de 2014 em sete locais: quatro na área costeira adjacente à região de Cananéia e três na área estuarina Mar Pequeno. A abundância dessas espécies foi comparada de acordo com a distribuição espacial (entre sítios) bem como entre anos e estações. Um total de 396 indivíduos de P. punctata e de 64 de P. mediterranea foram capturados. A abundância de ambas as espécies foi maior no segundo ano de coleta (julho de 2013 a junho de 2014). A abundância de ambas as espécies foi maior na área costeira, e apenas um indivíduo de cada espécie foi capturado na área estuarina devido à baixa salinidade neste local (27.7‰ aproximadamente). A temperatura foi o fator ambiental que afetou significativamente a distribuição das espécies, com maiores abundâncias em períodos mais quentes. A variação temporal da abundância foi modulada pela temperatura, enquanto a salinidade modulou a distribuição espacial de P. punctata e P. mediterranea. Em Cananéia as espécies não apresentaram diferenças na distribuição espaço-temporal, o que nos permite assumir elas habitam a área de uma forma muito similar.

Modulating factors of the abundance and distribution of Achelous spinimanus (Latreille, 1819) (Decapoda, Portunoidea), a fishery resource, in Southeastern Brazil.

This is the first study to examine how different environmental factors may influence the distribution of swimming crab Achelous spinimanus across geographically distant and distinct habitats. We analyzed the influence of bottom water temperature and salinity, sediment texture and organic matter content on the spatiotemporal distribution of A. spinimanus. The crabs were collected from January 1998 until December 1999 by trawling with a shrimp fishing boat outfitted with double-rig nets. The sampling took place in Ubatumirim (UBM), Ubatuba (UBA) and Mar Virado (MV) bays, located in the northern coast of São Paulo State (Brazil). These three bays were chosen as they differed in many physiographic features. We captured 1,911 crabs (UBM = 351; UBA = 1,509; MV = 51), and there were significant differences in abundance between bays and between stations. The distribution of A. spinimanus was primarily associated with sediment features: abundance was higher in stations with sandy sediments classified as gravel, very coarse sand, and intermediate sand. Portunoidea usually burrow in the sediment for protection against predators and to facilitate the capture of fast prey. In addition, the station with the highest abundance of A. spinimanus was also naturally protected from fishing activities, and composed of heterogeneous sediment, in terms of grain size. Hence, the combination of a favorable sediment heterogeneity and protection from fishery activities seemed to be effective modulators of the abundance and distribution of A. spinimanus in these bays.

Growth, longevity, and juvenile recruitment of the white shrimpLitopenaeus schmitti (Burkenroad, 1936) (Decapoda: Penaeoidea) insoutheastern Brazil / Crescimento, longevidade e recrutamento juvenil do camarão-branco Litopenaeus schmitti (Burkenroad, 1936) (Decapoda: Penaeoidea) na região Sudeste do Brasil

Litopenaeus schmitti is one of the most commercially exploited penaeids on the southeastern and southern Atlantic coast of Brazil. Information about juvenile recruitment and growth patterns of individuals is important for management programs. The present study estimated the growth parameters, longevity, and recruitment of L. schmitti in the region of Ubatuba, São Paulo State. The growth parameters of individuals were estimated by the Bertalanffy growth model, and longevity was estimated with the inverted Bertalanffy equation. The growth parameters were, for females and males respectively: CL∞ = 53.10 mm and 43.23 mm, k = 1.82 year-1 and 2.19 years-1, t0= 1.10 and 0.69. Longevity was calculated to be 2.27 years for females and 2.10 years for males. Juvenile recruitment occurred seasonally from December to April during the first year of sampling and from November to May in the second year. Although the large peak in juveniles seen in March 2007 in the estuarine regions coincided with the closed season, the reopening of the fishery in June may promote the capture of large numbers of newly grown adults who have not yet reproduced.

Litopenaeus schmitti é um dos peneídeos mais explorados comercialmente na costa do Atlântico Sudeste e Sul do Brasil. Desta forma, informações acerca do recrutamento juvenil e dos padrões de crescimento dos indivíduos são importantes para futuros programas de manejo. O presente estudo teve como objetivo estimar os parâmetros de crescimento, longevidade e recrutamento de L. schmitti na região de Ubatuba, Estado de São Paulo. Tais parâmetros foram estimados pelo modelo de crescimento de von Bertalanffy e a longevidade foi estimada por meio da equação inversa de von Bertalanffy. Os parâmetros de crescimento estimados para fêmeas e machos foram, respectivamente: CC∞ = 53,10 mm e 43,23 mm, k = 1,82 anos-1 e 2,19 anos-1, t0 = 1,10 e 0,69, e longevidade de 2,27 e 2,10 anos. O recrutamento juvenil ocorreu sazonalmente entre dezembro e abril no primeiro ano de amostragem e de novembro a maio no segundo ano. Embora o principal pico de juvenis, na região estuarina em março/2007, tenha coincidido com o período de fechamento da pesca, a reabertura da pesca em junho, possivelmente, promove a captura de grandes quantidades de recém-adultos, que ainda não participaram da primeira reprodução.

Associações entre as biomassas de peixes Sciaenidae (Teleostei: Perciformes) e de camarões Penaeoidea (Decapoda: Dendrobranchiata) no litoral norte do Estado de São Paulo / Relationships among Sciaenidae fish (Teleostei: Perciformes) and Penaeoidea shrimp (Decapoda: Dendrobranchiata) biomass from the north coast of São Paulo State, Brazil

Visando analisar as associações entre as biomassas de peixes Sciaenidae e de camarões Penaeoidea, foram feitas amostragens com barco de arrasto nas quatro estações do ano de 2001, em um gradiente de profundidade, nas regiões de Ubatuba, Caraguatatuba e São Sebastião. Em cada transecto, foram obtidas amostras de água e de sedimento. As hipóteses de que os fatores ambientais foram diferentes entre as estações do ano e profundidades foram testadas por ANOVAs. A dependência estatística entre as biomassas de peixes (variável resposta) e as biomassas de camarões (covariável) nas três regiões, foi testada por um modelo de ANCOVA. Para quantificar as relações entre as biomassas de cada espécie foi utilizada a CCA. A importância das estações do ano e das regiões no resultado da CCA foi avaliada pelo teste de Kruskal-Wallis e da profundidade pelo teste de Spearman. Nas estações do ano, as temperaturas e salinidades foram significativamente diferentes, o que não ocorreu com matéria orgânica (MO) e o diâmetro médio do sedimento (phi = fi). Foram amostrados 378.618 g de peixes e 79.338 g de camarões, com maiores capturas no inverno e nas menores profundidades. Em Caraguatatuba foram coletadas as maiores biomassas de ambos os grupos e a correlação entre as capturas de peixes e de camarões foi negativa. Já nas demais regiões, a correlação foi positiva. Assim, os dados de Caraguatatuba foram retirados do modelo final da ANCOVA, onde 47 por cento da variabilidade na biomassa dos peixes Sciaenidae pôde ser explicada pela presença dos camarões Penaeoidea. Xiphopenaeus kroyeri foi o único fator importante na distribuição de Sciaenidae no eixo 1, enquanto o eixo 2 evidenciou indiretamente o gradiente de profundidade. Os resultados sugerem que, possivelmente, muitas espécies de peixes busquem as mesmas áreas de ocorrência dos camarões em função dos fatores abióticos ou para utilizá-los como recurso alimentar.

To study the relationships among Sciaenidae fish and Penaeoidea shrimp biomass, fieldwork was carried out in the north coast of São Paulo state, Brazil, during the four seasons of 2001. Samples were collected in transects from different depths at Ubatuba, Caraguatatuba, and São Sebastião cities. Water and sediment were collected from each transect. The hypotheses that the environmental factors were different among the seasons and depths were tested by ANOVAs. The statistical dependence among the biomasses of fishes (response variable) and the biomasses of shrimps (covariable) in the three sections was tested by an ANCOVA model. CCA was used to quantify the relationships among each species' biomass. The seasons and sections important at the CCA results were evaluated by Kruskal-Wallis test and depth by Spearman's test. The temperatures and salinities were significantly different among seasons but organic matter and phi were not. A total of 378,618 g of fish and 79,338 g of shrimp were collected and the majority was captured during the winter and in shallow transects. The greatest biomass of both groups was captured at Caraguatatuba and the correlation between fish and shrimp captures was negative. A positive correlation was found in the other areas. Therefore, data from Caraguatatuba was removed from the final ANCOVA model, in which 47 percent of Sciaenidae biomass variability was explained by the presence of Penaeoidea shrimps. Xiphopenaeus kroyeri was the only important factor in Sciaenidae distribution in the axis 1, while axis 2 indirectly evidenced the depth gradient. The results suggest that many fish species search for the same areas where shrimp occurs, related to abiotic factors, and use them as food resource.