Genital organ anomalies in Xiphinema dentatum (Nematoda : Longidoridae)

Abstract

Seven specimens of Xiphinema dentatum with abnormal genital organs were found in the same population. Normal females are amphidelphic with the vulva located slightly anterior to the mid-body. Of some 24 000 females examined, six were found to be abnormal. One has a normally developed genital tract, but located in an abnormally posterior position. Two females have two complete systems each, one system in the normal position, and the other well posterior. Another female has a normal posterior branch, while the anterior one is abnormally branched at the pars dilatata uteri into two oviducts and ovaries, one ovary being degenerate. Another two females lack central parts of the system, the remaining distal parts being fused proximally. Males are rare in this species, sometimes having a fully developed diorchic genital tract, but usually with only the copulatory apparatus developed. Of the 137 males examined, one has a normal copulatory apparatus, lacks the seminal duct and has two abnormal masses of tissue corresponding to the position where the testes would normally be located.