Biologia reprodutiva do camarão sete-barbas no litoral centro sul e sul do Espírito Santo, Brasil

Abstract

RESUMOO tamanho de primeira maturação, ciclo reprodutivo e razão sexual do camarão sete-barbas Xiphopenaeus kroyeri foram estudados a partir de amostras mensais em duas áreas litorâneas do Estado do Espírito Santo, entre 2003 e 2004, visando subsidiar futuras medidas de manejo. As coletas foram feitas com redes de arrasto de fundo em pequenos barcos de pesca artesanais , entre 4 e 8 m de profundidade. Foram capturados 6.006 exemplares sendo 2.766 fêmeas, 3.182 machos e 58 de sexo indeterminado. As fêmeas foram significativamente maiores do que os machos. O comprimento médio de primeira maturação gonadal das fêmeas foi de 9,026 cm. As fêmeas adultas foram mais numerosas do que os machos entre dezembro e fevereiro, coincidindo com o pico de desova, enquanto que os machos adultos predominaram no trimestre subsequente. Essa alternância de proporções foi associada a migrações batimétricas reprodutivas das fêmeas. O ciclo anual de maturação gonadal, a abundância sazonal, variação dos tamanhos médios e a presença sazonal de juvenis sugerem a existência de desova contínua e recrutamento de dezembro a fevereiro e em julho e agosto. As dificuldades de se estabelecer um período de defeso adequado no estado indicam que o manejo do recurso deva receber maior atenção devido aos aspectos envolvidos, sejam sociais, biológicos ou ambientais.Palavras chave: Xiphopenaeus kroyeri; reprodução; recrutamento; defeso; razão sexual; pesca artesanal BIOLOGY OF THE SEA-BOB SHRIMP FROM THE ESPÍRITO SANTO COAST, BRASIL ABSTRACTThe size at first maturity, reproductive cycle, sex ratio and recruitment of the sea-bob shrimp Xiphopenaeus kroyeri were studied from monthly samples in two coastal areas of the Espírito Santo state between 2003 and 2004 in order to support sustainable management of this species. The samples were obtained with bottom trawls in small artisanal fishing boats from 4 to 8 m deep. A total of 6,006 specimens were captured being 2,766 females, 3,182 males and 58 of undetermined sex. Females were significantly bigger than males. The average length of first maturation of females was 9.026 cm. Adult females predominated over males between December and February, coinciding with the spawning peak, while males predominated in the subsequent quarter. This alternation of proportions was associated with bathymetric migrations of reproductive females. The annual gonadal maturation cycle, seasonal abundance and sizes and recruits suggest the existence of continuous spawning and recruitment in December-February and in July and August. The difficulties of establishing a closed season in proper condition indicated that the management of the resource should receive more attention because of the issues involved, whether social, biological or environmental.

POPULATION BIOLOGY OF SEABOB-SHRIMP Xiphopenaeus kroyeri (Heller, 1862) CAPTURED ON THE SOUTH COAST OF PERNAMBUCO STATE, NORTHEASTERN BRAZIL

“…HARTNOLL (1982) interpreted the larger size and greater weight of females as a functional difference related to the need to accommodate the ovaries and other reproductive organs. Similar results have been obtained for other X. kroyeri populations (SANTOS et al, 2001;CASTRO et al, 2005;LOPES et al, 2010;HECKLER et al, 2013b;MARTINS et al, 2013).…”

“…The shortest mature female was 6.5 cm in length (Lt), while all those of over 11.5 cm in length were mature. MARTINS et al (2013) recorded a similar L50 value of 9.02 cm for X. kroyeri off the central and southern coast of the Brazilian state of Espírito Santo. Variations in the L50 values among different geographic regions may be related to environmental factors, such as seasonality, latitude, and the depth of the water (DALL et al, 1990), or to differences in harvesting levels, which may provoke modifications in the timing of sexual maturation (SPARRE; VENEMA, 1997;FONTELES-FILHO, 2011).…”

“…However, considering the females and grouped sexes (the ideal parameter for management purposes), it is clear that the resource is close to the threshold of maximum sustainable yield. Xiphopenaeus kroyeri is known to spawn intermittently (MARTINS et al, 2013). This characteristic, together with its short life cycle, rapid growth and development, and high rates of natural mortality indicate that the species is resilient, and that its stocks may recuperate more rapidly than those of other species with longer life cycles.…”

“…To define size at first sexual maturity in the females, the percentage of adults by length class (dependent variable y) was calculated for each 0.5 cm size class and plotted against total length (independent variable x). Specimens were considered to be adults when they presented well-developed or spent gonads, as defined by CAMPOS et al (2009) andMARTINS et al (2013). These values were adjusted to a logistic curve using an iterative least squares approach, to obtain the value of L50 using KING'S (1995) logistic equation:…”

Carcinofauna bêntica estuarina de dois manguezais da costa amazônica maranhense, Brasil

“…Os crustáceos decápodes têm sido estudados em vários manguezais do Brasil sob aspectos distintos, abordando sua diversidade e distribuição (Silva & Almeida, 2002;Almeida et al, 2006;Nicolau & Oshiro, 2007;Nabout et al, 2009;Moreira et al, 2010;Negromonte et al, 2012, Araújo et al, 2014, bioecologia (Castiglioni et al, 2006;Araújo & Calado, 2008;Castro et al, 2008;Lima et al, 2010a;Menezes et al, 2012), reprodução (Baptista-Metri et al, 2005;Castiglioni & Negreiros-Fransozo, 2006;Castiglioni & Coelho, 2011;Castiglioni et al, 2013;Santos et al, 2008;Cobo & Fransozo, 2005;Martins et al, 2013) e até mesmo técnicas de industrialização de sua carne (Ogawa et al, 2008;Silva et al, 2013;Pinheiro et al, 2015).…”