Raosentis

Raosentis is a genus of Acanthocephala (thorny-headed worms, also known as spiny-headed worms) that parasitize the intestine of fish. ==Taxonomy== The National Center for Biotechnology Information does not indicate that any phylogenetic analysis has been published on Raosentis that would confirm its position as a unique order in the family Quadrigyridae.

==Description== The genus Raosentis is characterized by the trunk spines are restricted to anterior region only (not divided into two separate regions). The anterior trunk has 16-17 circles of spines and 4 circles of proboscis hooks with anterior two circles larger than posterior two circles; and a spineless space between 2nd and 3rd circles. Species in the genus have a small fusiform body with small hypodermic nuclei arranged in 4 or 5 pairs dorsally and 1 or 2 ventrally. The proboscis is globular to elongate with four circles of proboscis hooks, anterior two circles of hooks longer and shorter than posterior two circles with hookless free space in between. The proboscis sheath is single layered with ganglion at base. The Anterior trunk has 16-17 circles of rose-thorn spines. Testes contiguous, tandem, and near the posterior extremity. Cement gland syncytial with 8-10 nuclei. Vagina has two sphincters. Eggs are small and elliptical. Species are distinguished by 1. Ratio of size of proboscis hooks. {|class="wikitable" style="text-align: center; font-size: 75%;" |- ! colspan="7"|Female measurements (mm) |- !Measurements||R. cavasii||R. dattai||R. godavarensis||R. ivaniosi||R. podderi ||R. thapari |- |Length of proboscis|| || || || || || |- |Width of proboscis|| || || || || || |- |Length of proboscis receptacle|| || || || || || |- |Width of proboscis receptacle|| || || || || || |- |Length of trunk|| ||1.54-2.74|| ||2.0-7.0|| || |- |Width of trunk|| ||0.45-0.90|| ||0.85-2.0|| || |- |Length of small rootless spines|| || || || || || |- |Length of lemnisci|| || || || || || |- |Size of eggs|| ||0.040-0.045 x 0.02-0.022|| ||0.040-0.060 x 0.020-0.030|| ||0.039-0.04 x 0.02-0.022 |- ! colspan="7" |Male measurements (mm) |- |Length of proboscis|| || || || || || |- |Width of proboscis|| || || || || || |- |Length of proboscis receptacle || || || || || || |- |Width of proboscis receptacle || || || || || || |- |Length of trunk|| || || ||1.5-5.0|| || |- |Width of trunk|| || || ||0.3-0.67|| || |- |Length of small rootless spines || || || || |||| |- |Length of lemnisci|| || || || || || |- |Size of anterior testis|| || || || || || |- |Size of posterior testis|| || || || || || |- |Size of cement glands|| ||0.21-0.25 x 0.18-0.20|| ||0.120-0.200 x 0.200-0.250||0.32-0.52 × 0.16-0.35||0.28–0.33 × 0.13–0.20 |- |}