Biological aspects of Mithraculus forceps (Brachyura: Mithracidae) from Anchieta Island, Ubatuba, Brazil

Abstract

The population structure of Mithraculus forceps sampled monthly on Anchieta Island from January 1999 to December 2000 was studied. A total of 68 individuals were collected by SCUBA diving. The population presented normal and unimodal distribution, and the total sex ratio was 1·4:1·0 in favour of males. Ovigerous females were captured during all seasons. The pattern observed for the M. forceps population in Anchieta Island indicated the strategy favoured by environmental characteristics of the island and by coexistence with other decapod crustaceans in the studied area.

Características populacionais de Microphrys bicornutus (Brachyura, Mithracidae) no fital Halimeda opuntia (Chlorophyta, Halimedaceae), em área recifal submetida à visitação humana, em João Pessoa, Paraíba

“…Enquanto resultados obtidos para Mithraculus forceps (A. Milne-Edwards, 1875) (MANTELATTO et al, 2003) e para M. bicornutus (LÓPEZ GRECO et al, 2000;CARMONA-SUÁREZ, 2007) mostraram que a razão sexual dessas espécies tende a ser de 1:1, para Hyas coarctatus Leach, 1815 e Inachus dorsettensis (Pennant, 1777) (HARTNOLL et al, 1993) é evidenciado um desvio favorável à predominância de fêmeas, durante a passagem da fase imatura para a madura. Os valores detectados em H. opuntia denotam que, independentemente do estágio de desenvolvimento sexual, a proporção entre os sexos é praticamente constante, exibindo significativa superioridade numérica de machos.…”

Majoid crabs community (Crustacea: Decapoda) from infralittoral rocky/sandy bottom of Anchieta Island, Ubatuba

“…A similar pattern of occurrence of hermit crabs (Fransozo et al, 1998;Mantelatto and SouzaCarey, 1998;Mantelatto and Garcia, 2002) and brachyuran crabs (Fransozo et al, 1992;Hebling et al, 1994;Mantelatto and Corrêa, 1996;Mantelatto and Fransozo, 2000) was also observed in the Ubatuba region. In addition, CarmonaSuárez (2000) studying three Mithraculus species, i.e., M. forceps, M. coryphe (Herbst, 1801) and M. sculptus (Lamarck, 1818), from islets in the Morrocoy National Park (Venezuela) and Mantelatto et al (2003) studying M. forceps population in the Anchieta Island, Ubatuba reported the same variation in seasonal occurrence of these animals. Anchieta Island is affected by three water masses, with different distribution patterns in the summer and winter (Castro Filho et al, 1987).…”

Ecological distribution and population features of Hexapanopeus paulensis Rathbun, 1930 (Crustacea: Decapoda: Xanthoidea) caught by bottom trawling in the southeastern coast of Brazil: implications for its population structure

“…This method was calculated in the PeakFit software package, version 4.12 (Sea Solve Software Inc. 1999-2003. A Kolmogorov-Smirnov two-sample test was used to detect any difference between male and female length frequency distribution.…”

“…Among those studies, we can point out those on: Callinectes ornatus Ordway, 1863; Mithraculus forceps (A. Milne-Edwards, 1875), Libinia spinosa H. Milne Edwards 1834, Persephona mediterranea (Herbst, 1794), Persephona punctata (Linnaeus, 1758), Persephona lichtensteinii Leach, 1817 and A. schmitti, which were studied, respectively, by Mantelatto and Fransozo (1999b), Mantelatto et al (2003), Braga et al (2007), Bertini et al (2010b), Almeida et al (2013), Almeida et al (2013), and Fransozo et al (2013). Therefore, in addition to influencing the temporal abundance variations of H. paulensis, the SACW plays a fundamental role in juvenile recruitment.…”