Abstract Plastic pollution represents a threat to marine ecosystems and has therefore been gaining space in the realm of public interest. In this study, we investigated the ingestion of food and non-food items (i.e., plastic particles) by fish and crabs. These animals are commonly collected by trawling with a double-ring net along the coast of Cananéia, state of São Paulo, Brazil; some of them are consumed as food by the local population. Fish and crab stomachs were removed and dissected, and their contents were examined under a stereoscopic microscope with an image-capturing system. The presence or absence of plastic was also registered. We examined 139 specimens of 16 fish species and 143 specimens of four crab species. The most frequent food items found in fish were unidentified food, followed by crustaceans, molluscs, polychaetes, and other fish; in crabs, the items were unidentified food, followed by crustaceans, molluscs and fish. Plastic particles were found in all fish species, representing 47.5% of the individuals analysed. In crabs, the incidence of plastic was lower, occurring in only two species (5% in Callinectes danae and 3% in C. ornatus). Only four fish species analysed had previous records of plastic ingestion in the scientific literature. The high incidence of microplastics in our study is worrying because they negatively affect the animals’ lives and can be transferred through the tropic web to top predators, including humans, through the ingestion of contaminated animals.

Abstract In the Atlantic Ocean, the shrimp Cuapetes americanus (Kingsley, 1878) is well distributed. This species has been studied regarding its taxonomic status, distribution records, and some biological and reproductive traits. However, its fecundity and reproductive aspects have never been evaluated in Brazilian waters before. SCUBA (Self Contained Underwater Breathing Apparatus) diving and Artificial Refuge Substrate were used to sample C. americanus specimens quarterly in a sheltered location in the Marine State Parks of Laje de Santos and Vitória Island for a year (2015-2016). A total of 45 animals (carapace length 1.35-4.54 mm) were sampled: 6 females; 18 ovigerous females; 3 juveniles; and 17 males. The major axis references were employed to analyze the relationship between the second pleura (SPL) and the carapace length (CL). The fecundity was 87.05 ± 80.50 eggs and it was similar to other populations connected to it, and it was exclusively associated favorably with CL. Despite being a small and inconspicuous species, C. americanus is a caridean shrimp species that has evolved to thrive and breed on continental islands. The importance of the creation and revision of management plans for no-take marine areas on the Brazilian coast is supported when many kinds of information about the ecology and biology of the species are available, such as caridean shrimps, which can be present as a link between trophic levels of the aquatic food web.

Abstract Aeglids are endemic crustaceans from the Neotropical region of South America, with great importance in the freshwater food chain. We investigated the trophic relationships in different streams containing Aegla castro Schmitt, 1942 through the use of stable isotopes, testing the hypothesis that these animals occupy a lower position and that the environments are different and will modulate the isotopic ratios of carbon and nitrogen. Aegla castro showed a low trophic level in all locations, being an important link between producers and other trophic levels. They present differences in their isotopic signature for the sampling areas, indicating that environment can be a factor that modulates the trophic webs. We did not find intraspecific differences in isotopic signatures, probably due to the similar food items consumed by both juveniles and adults foraging in the same locations. Studies like this are becoming increasingly important due to the rapid degradation of freshwater environments and the lack of trophic knowledge about these endemic animals. It is increasingly important to understand how environmental changes (such as through anthropogenic action) is interfering in freshwater trophic relationships, and how this can affect the permanence of aeglids.

Abstract INTRODUCTION: Mantis shrimps or siriboias are crustaceans belonging to the order Stomatopoda. They are known for their strong claws, which they use for defense and capturing their prey. They are classified into two groups: the spearers, which pierce the prey with sharp projections, and the smashers, which strike their prey with high-powered punches. These animals are highly feared by fishermen, and there are frequent anecdotal reports of human injuries caused by these crustaceans. METHODS: A questionnaire about injuries in humans caused by these stomatopods was administered to 23 fishermen of Colony Z10 in Ubatuba, São Paulo state, Brazil, and a survey of the literature on injuries in humans caused by these animals was carried out. RESULTS: The fishermen consider the mantis shrimp dangerous and avoid direct contact with them on account of the associated risk. We describe five reports of human injuries caused by these animals: four by the claws and one by the tail spikes. CONCLUSIONS: We describe the first aid treatment, prevention, and recommendations for such cases and propose the distribution of educational leaflets among the fishermen colonies.

Abstract The aim of this study was to evaluate the gonadosomatic index (GSI) and the weight/length ratio in important shrimp populations (Xiphopenaeus kroyeri (Heller, 1862), Litopenaeus schmitti (Burkenroad, 1936), Rimapenaeus constrictus (Stimpson, 1874)) from the northern littoral of São Paulo State. The samples were collected between 2015 and 2016, with 212 females that were identified, classified according to their gonadal development stage, and measured (CL). The gonads were macroscopically classified into immature, spent and developed, and were then removed. Both body (BodW) and gonad (GonW) dry weights were obtained in order to calculate the gonadosomatic index. Weight/length relationship and weight gain rate were assessed. The weight gain presented negative allometry, indicating that the animals grow faster than they gain weight. The weight/length relationship showed a pattern of continuous reproduction, as previously determined for tropical species. From the GSI values, it was possible to separate the three predetermined gonadal stages, proving that macroscopic evaluation is reliable for evaluating the reproductive period of these shrimps. These results can be used as a guide for fishery stocks management and monitoring.

ABSTRACT This study investigated the population dynamics of Persephona punctata with emphasis on population structure, sex-ratio, spatial distribution, maturity and reproductive period. Crabs and environmental factors (i.e., water temperature and salinity, and sediment texture and organic matter content) were collected monthly, from July 2012 to June 2014 in four sites within the Federal Environmental Protection Area of Cananéia-Iguape-Peruíbe: located in the oceanic area adjacent to the Cananéia region. The population had a female-biased sex-ratio. Persephona punctata had a seasonal reproduction and the higher percentage of ovigerous females (OF) occurred in spring and summer. There was a positive correlation (“lag 0”) between temperature and number of OF (cross-correlation, p < 0.05) and a negative correlation between salinity and OF (“lag-2”), suggesting that periods of higher salinity may be favorable to larval hatching. The estimated size (carapace width - CW50) at the onset of gonadal maturity of males (35.0 mm) was larger than that of females (30.1 mm), which is a common feature of Brachyura. Our results extend the knowledge on the life history of P. punctata and may be useful for the development of future mitigation measures aimed at its conservation.

Abstract While previous studies on Alpheus formosus Gibbes, 1850 focused on taxonomic and phylogenetic issues, the present study provides information on the biology and ecology of this snapping shrimp, a representative coral reef species widely distributed in the Atlantic Ocean. We studied A. formosus between 2015 and 2016 on two islands in São Paulo state, Brazil: Laje de Santos and Vitoria Island. We analyzed 47 specimens from Laje de Santos and 44 from Vitoria Island. Individuals ranged in size from 2.0 mm to 13.99 mm CL. The mean number of embryos attached to the pleopods of females was 211.28 ± 312.8 in Laje de Santos and 125.2 ± 177.8 in Vitoria Island. This species should be included in monitoring programs of coral ecosystems they inhabit as A. formosus represents a key element in trophic dynamics of these ecosystems.

Abstract We estimated the growth parameters of the spider crab, Libinia ferreirae (age, asymptotic size and growth rate) using the von Bertalanffy growth equation model. We obtained nine cohorts for female carapace asymptotic width (CW∞) = 64.32 mm, growth coefficient (day-1) (k) = 0.0027 e t0= 0.77 days) and seven for males (CW∞ = 81.93 mm, k= 0.0021 e t0= 0.49 days). The longevity for males was higher than that for females, estimated 2,156 days (5.91 years) and 1,706 days (4.68 years), respectively. The growth curves for males and females differed (F = 34.67 e p < 0.001). Males reached gonadal maturity before morphometric maturity and occurred at 8.8 and 16.6 months of life, respectively. Females reach gonad and morphometric maturity synchronously and this was estimated to occur at about 11.42 months of life. These crabs invest a great amount of energy in growth during a brief period of their development until reaching the terminal moult. This growth strategy would bring less wear to the organism and consequently a greater longevity.

Abstract We aimed to analyze the crustacean bycatch from the Xiphopenaeus kroyeri fishery in the Santa Catarina State and compare the bycatch’s biomass to that of the target species. Shrimp and environmental factors were sampled monthly from July 2010 through June 2011. For each crustacean species, we calculated the number of individuals, the relative abundance and the occurrence frequency. The relative abundance was classified as very abundant (Va), abundant (Ab) or low abundance (La), while the occurrence frequency was labeled continuous (Co), accessory (Ac) or accidental (Ad). We observed a total richness of 28 species, which is considered high for a subtropical region. Brachyura was the most frequent taxon (74%) followed by Penaeiodea (18%). Five species were considered Va (Arenaeus cribrarius, Callinectes danae, C. ornatus, Isochelis sawayai and Pleoticus muelleri), and eight species were considered Co (A. cribrarius, C. danae, C. ornatus, Farfantepenaeus paulensis, Hepatus pudibundus, Libinia spinosa, Litopenaeus schmitti and Sicyonia dorsalis), suggesting that the studied environment is heterogeneous and provides a variety of microhabitats, enabling many species to coexist. Therefore, the high species richness observed demonstrates the ecological importance of this region and thus the necessity of strategies aiming to minimize the impacts caused by trawling fisheries.

Abstract: This study analyzed the taxa associated as epibionts with mollusc shells inhabited by the hermit crab Isocheles sawayai, in order to understand how they affect host crabs. A total of 575 individuals were collected, including 156 females, 103 ovigerous females, and 316 males, which occupied shells of 10 species of gastropods. The epibionts recorded in the shells of I. sawayai belonged to Cirripedia, Polychaeta, Bivalvia, Anthozoa, Demosponge, and Bryozoa. A larger percentage of infestation occurred inside the shell, which may be harmful to the hermit crab because it reduces the internal volume. Ovigerous females used shells with a smaller percentage of infestation (40%), which may be related to the need for more space for the position and development of fertilized eggs. However, a higher proportion of anemones was found in shells used by ovigerous females. The advantage of this association for the anemones and crabs is discussed. The results suggest that shells occupied by epibionts can be a favorable factor for hermit crab survival, mainly for ovigerous females.

Resumen: Los taxones asociados como epibiontes con conchas de molusco usadas por el cangrejo ermitaño Isocheles sawayai fueron analizados para comprender como afectan al cangrejo hospedero. Se recolectó un total de 575 individuos, 156 hembras, 103 hembras ovígeras y 316 machos que ocuparon conchas de 10 especies de gasterópodos. Los epibiontes registrados en las conchas de I. sawayai pertenecieron a: Cirripedia, Polychaeta, Bivalvia, Antozoa, Demospongia y Bryozoa. Dentro de la concha, el porcentaje de infestación fue mayor, lo que puede ser perjudicial para el ermitaño, ya que reduce el volumen interno. Las hembras ovígeras utilizaron conchas con menor porcentaje de infestación (40%), lo que puede estar relacionado con la necesidad de más espacio disponible para la ovoposición y el desarrollo de los huevos fertilizados. Sin embargo, hubo una mayor proporción de anémonas en conchas ocupadas por hembras ovígeras. Se discute la ventaja de esta asociación para las anémonas y los cangrejos. Los resultados muestran que las conchas ocupadas por epibiontes pueden ser un factor favorable para la supervivencia del ermitaño, especialmente para hembras ovígeras.

Abstract This study analyzes ontogenetic allometry in Aegla marginata Bond-Buckup & Buckup, 1994, a freshwater crustacean, in order to evaluate the growth pattern and the presence of sexual dimorphism, using a multivariate approach. The specimens were sampled from streams in Intervales State Park, São Paulo State, Brazil. For each specimen, we measured the following structures: carapace length and width, chelae height and length, and abdomen length. Allometry was evaluated using Jolicoeur’s multivariate allometric coefficient. Our results showed that for females, ABL (abdomen length) and LCH (left chelae heigh) presented positive allometry; LCL (left chelae length) and RCH (right chelae heigh) isometry; and CL (carapace length), CW (carapace width), and RCL (right chelae length) negative allometry. For males, RCH, LCH, and LCL presented positive allometry; RCL (right chelae length) isometry; and CL, CW, and ABL negative allometry. In addition, sexual dimorphism was amplified with body size.

Abstract The spatio-temporal distribution of juveniles of the pink shrimps Farfantepenaeus brasiliensis (Latreille, 1817) and Farfantepenaeus paulensis (Pérez-Farfante, 1967) in the Ubatuba region (SP) was investigated. Sampling was performed in the bays of Ubatumirim (UBM), Ubatuba (UBA) and Mar Virado (MV). A total of 2,018 F. brasiliensis and F. paulensis were collected. The largest catch of juveniles of both species occurred in UBA (N = 867), followed by UBM (N = 729) and MV (N= 422). The bottom sediment in MV had the highest silt and clay content, which explains the negative correlation of the substrate with the abundance of both species. Temperature was positively correlated with the abundance of both species. Juveniles were highly abundant in shallower areas in the summer of 1998. The high rainfall in this El Niño period may have lowered the salinity in estuarine waters and led the shrimps to move to coastal areas in search of higher salinities such as in bays. With this unusually early reduction in salinity, individuals migrated to the bay before the closed season began and thus became more exposed to fishing. We confirmed that monitoring environmental variations, especially in El Niño years, is essential for understanding the distribution patterns of juveniles of both species.

A variação diuturna na abundância e no tamanho de Pleoticus muelleri foi investigada na região de Ubatuba durante o ano de 2000. Em cada estação do ano, as coletas foram realizadas no período diurno e noturno em 8 profundidades, de 5 a 40 m. O número estimado de camarões foi de 955 indivíduos, 272 coletados durante o dia e 683 à noite. Houve diferença na abundância de P. muelleri entre o dia e a noite (χ², p=2.33E-40). A abundância durante o dia e à noite diferiu por estação com exceção da primavera (χ², p=0.06). A abundância em ambos os períodos também diferiu por profundidade, exceto nos 15 e 30 metros (χ², p=0.84 e 0.06, respectivamente). Os camarões capturados à noite foram geralmente menores do que os capturados durante o dia (Kolmogorov-Smirnov, p<0.01). Os juvenis de Pleoticus muelleri foram encontrados principalmente à noite e tal tendência pode ter influenciado no menor tamanho médio obtido nesse período. O tipo de sedimento e a temperatura de fundo parecem influenciar o comportamento da espécie em questão e, consequentemente, a taxa de captura durante os períodos analisados.

Diel variation in the abundance and size of Pleoticus muelleri in the Ubatuba region was investigated during 2000. During each season of the year, sampling was conducted during the day and at night at 8 depths, from 5 to 40 m. The estimated number of shrimp was 955 individuals, 272 collected during the day and 683 at night. There was a difference in the abundance of P. muelleri between day and night (χ², p=2.33E-40). The abundance during the day and at night differed by season with the exception of the spring (χ², p=0.06). The abundance during both periods also differed by depth, except at 15 and 30 m, where it was not significant (χ², p=0.84 and 0.06, respectively). The shrimp caught at night were generally smaller than those caught during the day (Kolmogorov-Smirnov, p<0.01). Pleoticus muelleri juveniles were found primarily at night. This tendency could have influenced the lower mean size for this period. The sediment type and the bottom temperature appear to influence the behavior of this species and consequently the catch rate during the periods analyzed.