Reproductive cycle of Mellita quinquiesperforata (Leske) (Echinodermata, Echinoidea) in two contrasting beach environments

Abstract

The reproductive cycle of the irregular echinoid Mellita quinquiesperforata (Leske, 1778) was studied in populations from two sand beaches with different morphodynamic conditions in Parana coast, from February 1992 through July 1994. Gametogenesis was described by histological and gonad index methods and the differences between both populations were observed in the extension of nutrient storage and spawning period. Both populations exhibited a main reproductive period during spring/summer and a nutrient storage period during autumn/winter months. The spawning period at the intermediate-dissipative beach was shorter than at the reflective beach. Meanwhile, a nutrient storage stage was more extensive in the latter. Gonad index varied between both sexes and it was influenced by population characteristics. Different strategies in allocation of resources between maintenance and reproduction effort (oocyte size) confirm the high adaptive plasticity developed by this species to live in contrasting beach environments.

Echinodermata da Praia do Cabo Branco, João Pessoa, Paraíba, Brasil

“…Para as regiões sul e sudeste são conhecidos diversos trabalhos enfocando o grupo como um todo (Krau 1950, Brito 1971, Hadel et al1999, Netto et al 2005, Ventura et al 2006, 2007, bem como estudos mais concentrados em classes específicas (Tommasi 1970b, Manso 1988a, b, c, d, 1989, 1993, Manso & Absalão 1988, Borges et al 2002, Borges & Amaral 2006-Ophiuroidea, Tommasi 1965, 1969b, MacCord & Duarte 2002-Crinoidea, Tommasi 1969a, Tiago & Ditadi 2001, Mendes et al 2006-Holothuroidea, Tommasi 1966, Tavares & Borzone 2006-Echinoidea e Tommasi 1970a. O conhecimento sobre a fauna de equinodermos na Região Nordeste ainda é considerado escasso, principalmente nos estados do Piauí, Maranhão, Paraíba e Alagoas.…”

Do stranded sand dollars indicate hydrodynamic conditions of sandy beaches?

“…The size of the sand dollars was another favorable factor for their use as an indicator of the hydrological dynamics of Praia de Santos. Figure 4 shows a predominance of adult animals, with higher chances of reproducing before being released to the supra coast and dying [29][30][31][32][33][34] found that water turbulence induces behavioral responses to the transition of Pacific sand dollar larvae (Dendraster excentricus) from the planktonic to the benthic phase. This same phenomenon may not occur with the larvae of Melitta quinquesperforata, seen by the absence of younger individuals (below 4cm) that possibly occupy places distant from the surf zone of Santos beach.…”

First record of the heart urchin Plagiobrissus grandis (Gmelin, 1791) (Echinodermata: Echinoidea) in the coastal region of Paraná, southern Brazil

“…A gonadal tissue fragment (1 cm²) was removed through a small incision made under one of the interambulacral plates (1 cm²) for routine histotechnique procedures for hematoxylin and eosin (H&E). In the gametogenesis events description (Nunes & Jangoux, 2004;Tavares & Borzone, 2006, diagnoses were used for both regular echinoids: Lytechinus variegatus (Lamarck, 1816) (Toxopneustidae: Camarodonta) and irregular: Echinocardium cordatum (Pennant, 1777) (Loveniidae: Spatangoida) and Mellita quinquiesperforata (Leske, 1778) (Mellitidae: Clypeasteroida).…”