SEM OBSERV ATIONS ON TWO SPECIES OF HOPLOLAIMUS DADAY, 1905 (NEMATODA: HOPLOLAIMIDAE)

Abstract

The main morphometricaI characteristics of Hoplolaimus galeatus (Cobb 1913) Thorne 1935 and H. stephanus Sher, 1963 are amplified and supplemented with scanning electron microscope (SEM) observations, made on two bisexual American populations collected in natural habitats tram Pensacola, Florida and Raleigh, North Carolina, respectively. In both species lip region is hemispherical in profile, set off tram the body by a distinct constriction, having 4-6 annuli and an oral disc. Anterior cephalic annuli are marked by six longitudinal striae (two deep dorsal and ventral grooves and 4 shallower lateral), but the basal annulus is divided into (26-36 in H. galeatus; 30-36 in H. stephanus) irregular blocks. The lateral fields in both species have 4 incisures with outer and inner bands areolated. The main diagnostic features and measurements of both species are compared with all previous data.