Douglas Fernandes Rodrigues Alves

New records of decapod crustaceans from the coast of Sergipe state, Brazil

The objective of this study is to report seven decapod crustacean species for the first time from Sergipe state, northeastern Brazil. The specimens were sampled from January 2012 to June 2015, on continental shelf and estuaries. Alpheus buckupi, Synalpheus ul , Lysmata bahia , L. cf. intermedia , Paguristes tortugae , Macrocoeloma laevigatum and Pilumnoides coelhoi are reported. This study records fill gaps in the geographical distribution of these decapods that have previous records for adjacent areas.

Morphological remarks on the peppermint shrimp Lysmata ankeri (Decapoda, Hippolytidae): implications for species identification of the L. wurdemanni complex

This contribution reviews the morphology and the main diagnostic characters of the peppermint shrimp Lysmata ankeri. Individuals were sampled by scuba divers from August 2008 to June 2013 on the subtidal rocky bottom at Couves Island, on the coast of Sao Paulo State, Brazil. In the laboratory, the individuals were analyzed morphologically, with emphasis on the characters used in the diagnosis of the species; measured as carapace length (CL); and photographed. Seventeen individuals of L. ankeri were analyzed with an average size of 6.9 ± 2.0 mm CL. From the morphological analysis the following variations of the diagnosis were observed: five teeth on the dorsal margin of the rostrum, in the diagnosis this was 6-8; five spines on the flexor margin of the dactyli of pereiopods 2-4, in the diagnosis this was 3-4. The records of this study extend the knowledge of the variation of some morphological characteristics for this species, resulting in an overlap among the species of the Lysmata wurdemanni complex.

Relative growth and onset of morphological sexual maturity of the freshwater crab Sylviocarcinus pictus in a river of the Caatinga of northeastern Brazil

ABSTRACT The aim of this study was to investigate the relative growth and onset of morphological sexual maturity of the freshwater crab Sylviocarcinus pictus. Specimens were collected every month from October 2013 to September 2014, at night, on a stretch of the river Guaribas, Piauí, Brazil. Crabs were sexed and their carapace width (CW, independent variable), carapace length (CL), cheliped propodus length (PL) and height (PH), gonopod length (GL), and abdomen width (AW) (dependent variables) were measured. These measurements were related to characterise relative growth and possible sex differences. On average males were larger than females (p = 0.0001). Size at the onset of morphological sexual maturity was defined by relating CL vs. PL for males (30.82 mm) and CL vs. AW for females (28.63 mm). These are considered secondary sexual characters and reflect initial size at morphological sexual maturity with greater precision. The differential cheliped growth of males may be related to courting and disputes with other males, while the allometric growth of the abdomen of females indicates increased probability of reproductive success.

Reproductive output of the ornamental shrimp Lysmata vittata (Stimpson, 1860) (Decapoda: Caridea) in wild populations and under different maturation diets

ABSTRACT Reproductive output parameters (fecundity and egg volume) of Lysmata vittata were examined in a population in northeastern Brazil. Effect of maturation diets on the reproductive output of these shrimp under laboratory conditions was evaluated. Reproductive output was estimated for 25 shrimp collected in the wild. Another 45 pairs of shrimp were used for diet experiments, 15 pairs per treatment (T1: industrialized food, T2: fresh food, T3: mixed diets). For wild population, mean fecundity and egg volume were differed between developmental stages of the eggs. Fecundity was significantly lower in the specimens subjected to T1 diet (267 ± 141 eggs) compared with shrimp from the wild population (393 ± 183 eggs). Egg volume was significantly lower in shrimp subjected to three diets tested compared with those from wild population. Egg loss during embryonic development in L. vittata may be caused by several factors (e.g. aborted development and maternal cannibalism). Fresh food proved to be important for improving reproductive output in L. vittata reared in culture. We emphasize the significance of improving nutritional value and palatability of diets to improve cultivation efficiency. Lysmata vittata can be used as a model organism for future studies aiming to improve the cultivation techniques for shrimp of the genus. Abbreviations PSH: protandric simultaneous hermaphroditism; ARS: artificial refuge structures; CL: carapace length; EV: egg volume; L: largest diameter of the egg; S: smallest diameter of the egg; T1: industrialized pellets; T2: fresh ingredients; T3: mixed diets; ANCOVA: analysis of covariancr; SD: standard deviation.