DESENVOLVIMENTO LARVAL DO CARANGUEJO VIOLINISTA MINUCA RAPAX (OCYPODIDAE: GELASIMINAE) (SMITH, 1870), DA REGIÃO AMAZÔNICA, CULTIVADO EM CONDIÇÕES DE LABORATÓRIO

In the present study, we describe and illustrate in detail the complete larval development of the neotropical mangrove fiddler crab Minuca rapax, cultured under laboratory conditions. Larvae were obtained from an egg-bearing female that was collected in the mangroves of the Caeté River estuary, Pará State (North Brazil). After hatching, the larvae were cultured in 250 ml plastic vials (at a density of ca. 10 larvae per vial) at an ambient temperature of 26.7 ± 1.6 °C, salinity 30, pH 8.1 ± 1.0, with photoperiod regime (12h light/ 12h dark cycle) and without aeration in the culture medium. Rotifers (Brachionus plicatilis; ca. 200 individuals ∙ mL–1), microalgae (Thalassiosira sp.; ca. 4 x 104 cells ∙ mL–1) and brine shrimp nauplli (Artemia sp.; ca. 8 nauplii ∙ mL–1, only start from the third zoeal stage) were offered to larvae as food items. The early development of M. rapax consisted of 5 zoeal stages (ZI–ZV) plus a megalopal larval stage. All zoea larvae (ZI–ZV) survived with success in the culture. The development period of the ZI and ZII larval stages varied from 1 to 2 days, with averages of 1.8 ± 0.4 and 1.1 ± 0.3 days, respectively. The ZIII and ZIV stages developed from 1 to 3 days (2.0 ± 0.3 days), while the ZV stage developed within 3 to 5 days (3.9 ± 0.4 days). The total zoeal developmental period until moulting to megalopa ranged from 11 to 13 days (11.8 ± 0.6 days). The ZI and megalopal stages of M. rapax were morphologically compared with larvae from congeneric fiddler crab species previously described in the literature.