GROWTH AND METAMORPHOSIS IN TADPOLES OF RANA PRETIOSA PRETIOSA, TREATED WITH RECOMBINANT PORCINE GROWTH HORMONE, PROLACTIN, SOMATOSTATIN (SRIF) AND ANTI-SRIF

Abstract

The effect of prolactin (PRL), growth hormone (GH), somatostatin (SRIF) and anti-SRIF (αSRIF) treatment upon growth and metamorphosis of western spotted frog tadpoles, T a y l o r and K o l l r o s (1946) stage (TK st.) XVI (n = 18/group) was examined. Treated animals received 2.5 g protein/g body weight every 5 days until one group exhibited > TK st. XXIV and complete terrestrialization. Administration of GH and PRL resulted in 18/18 and 15/18 animals respectively expressing complete terrestrialization. 12/18 SRIF injected tadpoles achieved > TK st. XXIV. In contrast, only 5 each of control and SRIF treated tadpoles transformed to > st. XXIV. Significantly higher (P<0.05) length: weight ratios were recorded for control versus all other treatment groups. PRL and αSRIF treated animals exhibited reduced body length: fore limb length ratios (P<0.05) when compared to controls. Greater hind-limb length was noted in animals treated with GH, SRIF and PRL. PRL treatment resulted in significantly increased length and weight (P<0.05) when compared to controls, and highly significant (P<0.01) reduction in condition factor compared against all other treatment groups.

Keywords

• rana pretiosa pretiosa
• metamorphosis
• anti-somatostatin
• somatostatin
• prolactin
• growth
• growth hormone