Tallas y fecundidad de Juxtafabia muliniarum (Brachyura: Pinnotheridae) asociado con Saccostrea palmula (Bivalvia: Ostreidae), Costa Rica / Body size and fecundity of Juxtafabia muliniarum (Brachyura: Pinnotheridae) associated with Saccostrea palmula (Bivalvia: Ostreidae), Costa Rica

Size and fecundity observations of pea crab (Juxtafabia muliniarum) from the paleal cavity of the oyster Saccostrea palmula were made from May 1998 to May 1999. Infestation frequency was 18.52 in a sample of 540 oysters. Of 136 pea crabs, 36 were couples, 60 were single females and 4 were single males. The mean caparace length of J. muliniarum was 5.6 +/- 0.74 mm (range 4.0 to 7.6 mm) for females and 2.71 +/- 0.60 mm (range 1.6 to 4.0 mm) for males. The mean weight was 0.180 +/- 0.084 g (range 0.06 to 0.4 g) for females and 0.011 +/- 0.003 g (range 0.01 to 0.02 g) for males. Ovigerous females (43.75 of all females) were found in all months. The caparace length-fecundity relationship was F = 3904.6 Ln (Lc)--4651.1. The caparace length-weight relationship was P = 6 x 10(-4) Lc3.2122. The mean sex-ratio was 1.0 male: 2.4 females. Saccostrea palmula infected only by females was the dominant group (60.78). This mollusk is a new host record for the crab.

Mortalidad embrionaria y éxito de eclosion en huevos de Trachemys scripta (Testudines: Emydidae) incubados en un área natural protegida / Embryonic mortality and hatching rate of trachemys scripta (Testudines: Emydidae) eggs artificially grown in a protected natural area

In the northeast of Costa Rica, illegal collecting, habitat destruction and heavy predation on adult females, young and eggs of Trachemys scripta produced a population decline in recent years. The slider turtle has a high reproductive potential and nests were relocated. Between January and March 1991,179 nests (3220 eggs) were collected from natural areas of Ca o Negro National Wildlife Refuge, Costa Rica and relocated for incubation under natural conditions in a protected site. The mean of number of eggs per clutch was 19.5 +/- 4.5 (range 8 to 31) and the mean incubation period was 77.4 +/- 11.4 days (range 50 to 110 days). The mean hatching success was 89.6 +/- 3.4 percento (range 60.0 to 100 percento).The mean early and mid embryonic mrtality was 5.5 +/- 4.3 percento, the average late embryonic mortality was 8.5 +/- 3.5 percento and infertility 1.8 +/-1.0 percento

Crecimiento, conversión de alimento y mortalidad de Eretmochelys imbricata (Reptilia: Chelonidae) en estanques artificiles en Costa Rica / Growth, food conversion and mortality of Eretmochelys imbricata (Reptilia: Chelonidae) en estanques artificiales en Costa Rica

Growth rates, feed conversion and mortality of cultured Eretmochelys imbricata (hawksbill turtle) were studied in concrete raceways by feeding with fresh fish meal (tilapia) and in duplicate (tanks of 21 m2). The turtles were 11 months old at the beginning of the experiment, with and average caparace straight length of 23.64 +/- 1.94 cm, an average caparace curved length of 24.15 +/- 1.94 cm and an average weight of 1527 +/- 2.54 g. The experiment was carried out during six months and a density of 3 ind/m2 was used. The equation of Von Bertalanffy for the growth of E. imbricata was LRC = 3.5 + [(82.0 -3.5)(1-e-0.67432 (t))]. The relationship between caparace straight length-weight was W = 5.207 x 10(-3) LRC 3.8807 (r = 0.99). The feed conversion was 1.54 +/- 0.74 and the mortality was zero during the study