<b>Morphotypic differentiation of males of freshwater prawn <em>Macrobrachium amazonicum</em>: Changes in the hepatopancreas and the reproductive system</b> - DOI: 10.4025/actascianimsci.v26i4.1720

Abstract

Adult males of the freshwater prawn Macrobrachium amazonicum from a same-age population can be categorized in four morphotypes, according to external morphologic characteristics. Each morphotype represents a different stage in the growth of adult males, starting with translucent claw (TC), followed by cinnamon claw (CC), then green claw 1 (GC1) and, finally, green claw2 (GC2). However, they can be categorized three morphotypes, according to testis internal morphology. To clarify in part these observations, 40 male prawns were selected from a single-age population bred at the Aquaculture Center of Unesp. The reproductive system and the hepatopancreas of each animal, from all morphotypes, were measured and compared. The reproductive system growth was a sexual activity indicator. Also, hepatopancreas growth was found to be related to somatic growth. The hepatopancreas growth was significantly higher in the CC morphotype when compared to the TC morphotype, and the reproductive system growth was significantly higher in GC1 morphotype than in CC morphotype. All the males of the morphotypes TC, CC, GC1 and GC2 showed significant difference in body weigh; however, the difference between GC1 and GC2 morphotypes was due to the significant growth in the claw length and not to reproductive system and hepatopancreas