ANALYSIS OF MILT QUALITY AND TESTIS HISTOLOGICAL FEATURE OF POST-SPAWNING BAWAL (Colossoma Macropomum)

Abstract

The research aims to observe several reproductive parameters of Bawal/pomfret fish after spawning. Data on milt quality parameters were crucial for determining the readiness of male parent for successful spawning, while ensuring female parent has reached sexual maturity. The observation results on the quality of post-spawning male Bawal from week 0 (M0) to week 3 (M3) are as follows, milt volume=0.1 - 1.75 ml, Milt pH=6 - 7, sperm motility=35 - 100%, and the density or number of spermatozoa ranged from 2.03 x 1011 cells/ml (M0) to 3.56 x 1011 cells/ml (M2). Furthermore, the length of spermatozoa ranged from 40 to 60 μ, with a head length of only 2-3 μ. Supporting data on GMI of male parents was 2.57% (M0) - 4.02% (M2). The histological observations of testicular development showed that all stages of spermatogenesis were visible from M0 to M3 preparations, including spermatogonia, primary spermatocytes, secondary spermatocytes, spermatids, and spermatozoa. The proportions of each stage of spermatogenesis are as follows, (in %): M0 (spg=13.5; sp=15.3; ss=17.8; smt=15.1; spz=63.2); M1 (spg=5.3; sp=4.2; ss=10.6; smt=14.4; spz=61.2); M2 (spg=5.2; sp=6.3; ss=9.9; smt=9; spz=55.1); M3 (spg=6.0; sp=5.0; ss=30.5; smt=17.1; spz=52.5). Despite the good quality status of milt and GMI, only 4 out of 24 post-spawning male Bawal produced milt during stripping (M0-1, M0-2, M2-4, and M3-4), while the other 20 did not. This correlated with data obtained from Bawal farmers in Banyumas, Central Java, who reported that during the dry season, male Bawal had difficulty preparing for spawning, even when their reproductive quality status was relatively good