Description:-

Formalin preserved worms measured 15mm in length with one hundred and twenty- five segments. External segmentation well marked. Body tapering toward the posterior region. Brown bands of pigment occur in the anterior twenty-five segments, being very clear up to the eighteenth segment. No eyes. Prostomium small and conical. Gills beginning from the V segment, one pair per bundle. Forty-nine such pairs have been counted in the present specimen, all being restricted to the anterior region. These structures arise as dorso-lateral projections of the body wall with slight constriction at the place of attachment. Anterior gills are longer having a range in length between 0.15-0.20mm. Their length decreases toward the posterior region and at about the XL segment they become mere tubercles. Gills are highly vascularized, each gill with an afferent and efferent vessel, both being connected by capillaries. In the anterior region, three hair setae occur per bundle; all being embedded inside the gill and thus forming a supporting frame work for it. The number is reduced to two and one per bundle toward the posterior region. In the tubercles they project outside it. Hairs straight, smooth, 300-400µ long in the anterior segments, but comparatively smaller and thicker toward the posterior region. Needles single pointed, anodulate and straight anteriorly, but curved distally toward the posterior region. Ventral setae commencing from the second segment with four setae per bundle in the anterior region reducing to three and two toward the posterior region. Anterior setae have median nodulus with distal prong longer and thinner than the proximal. Toward the posterior region, the nodulus is distally placed with prongs of equal length. Asexual reproduction is observed to take place by a slight constriction after the XXXVIII segment.

Threats:-

Not recorded.

Remark:-

Habitat:-

Living in the bottom mud of the pond. Not tube dwelling.

Synonyms:-

Chaetobranchus semperi Bourne, 1890
Chaetobranchus semperi Bourne. Bourne, 1891
Branchiodrillus semperi (Bourne). Michaelensen, 1900
Branchiodrillus menoni Stephenson, 1912
Branchiodrillus menoni Stephenson. Stephenson, 1921

References:-

Sobhana, S. 1982. Studies on the biology of the aquatic oligochaetes of Kerala. MPhil Thesis submitted to University of Kerala. Dep.t of Aquatic biology and Fisheries.