Desarrollo embrionario del camarón de río Cryphiops caementarius (Decapoda: Palaemonidae) en condiciones de laboratorio

Abstract

Embryonic development of the freshwater shrimp Cryphiops caementarius (Decapoda: Palaemonidae) under laboratory conditions. We describe seven stages for the embryonic development of Cryphiops caementarius (Molina, 1782) using both light and scanning electron microscopy. Thirty ovigerous females were captured in Limarí River, Chile, and maintained separately in three 35 liter tanks with temperatures of 15, 22 and 28 ºC. At the same time, some embryos were separated from the females and placed in a 100 ml beaker for in vitro culture at 15 °C. Duration of development at 15, 22, and 28 ºC was of 36-39, 30-32 and 25-28 days, respectively, with no differences observed between in vitro and in vivo cultures. Seven development stages were observed: (I) homogeneously distributed vitellum; the embryo cleavage leads to the morulae stage; (II) first embryonic stage; antennule, antenna and ocular globe are present; (III) primordium lengthens, and the outlines of the pereiopods can be observed; ocular pigmentation appears as a curved line; (IV) ocular pigmentation in hemispherical form; the antennae develop, and the first red pigmentation appears near the eye; heartbeat is visible ; (V) the pereiopods touch the base of the antennae; the ocular globe is more evident, in a oval form; (VI) eyes are faceted, and both antenna and third abdominal segment with chromatophores; ocular pigmentation as spherical form; (VII) ocular globe with spherical eye pigmentation and facets on the surface; star-shaped chro-matophores on the appendages. Egg volume increased from 0.082 mm 3 at the beginning of the development to 0.125 mm 3 close to hatching, representing a rise of 65.6 %. The diameter of the embryo and eye pigmentation may be used as growth parameters. Rev. Biol. Trop. 55 (Suppl. 1): 15-24. Epub 2007 June, 29.