Allometric growth in three species of digenetic trematodes of marine fishes from Belize.

Allometric growth of body proportions and organs is determined for three speciies of digenetic trematodes of marine fishes from Belize: Apocreadium mexicanum Manter, 1937 (Apocreadiidae), Pseudocreadium lamelliforme (Linton. 1907) Manter, 1946 (Lepocreadiidae), Paracryptogonimus americanus Manter, 1940 (Cryptogonimidae). These are compared with three other species in which allometric growth has been studied. In all species only the hindbody shows positive growth, whereas the forebody, suckers, and pharynx are consistently negative. The body width, posttesticular body, testes, and ovary are positive in some species and negative in others. In some instances the body proportion or organ is growing at the same rate as the body length.