Ptycholaimellus macrodentatus, (Timm, 1961) Muthumbi & Vincx, 1998

Datta, Tridip Kumar, Chakraborty, Susanta Kumar & Mohapatra, Anil, 2017, First report of Ptycholaimellus macrodentatus (Timm, 1961) (Nematoda: Chromadorida) from Indian coast, Records of the Zoological Survey of India 117 (3), pp. 274-274 : 274-

P. macrodentatus (Timm, 1961) Muthumbi & Vincx, 1998

Synonym: Hypodontolaimus macrodentataus Timm, 1961

Specimens examined: Male: Reg. No. MARC/ZSI/N4131, L: 915 µm; Reg. No. MARC/ZSI/N4132, L: 805 µm; Reg. No. MARC/ZSI/N4133, L: 791 µm.

Female: Reg. No. MARC/ZSI/N4134, L: 978 µm; Reg. No. MARC/ZSI/N4135, L: 900 µm; Reg. No. MARC/ZSI/ N4136, L: 999 µm; Reg. No. MARC/ZSI/N4137, L: 1111 µm; Reg. No.MARC/ZSI/N4138, L: 946 µm.

Description (Figure 2-4 and Table 1 & 2)

Body cylindrical with bluntly rounded anterior end. Amphid indistinct, possibly situated at the head end as elongated aparture. Four cephalic sensilla about 8-10 µm in males and 10-13 µm in females. Head diameter varying 6-12 µm, measured at the level of cephalic sensilla. Cephalic sensilla little short or equal of head diameter. Outer labial sensilla papilliform originated little above the level of cephalic sensilla. Two small cervical setae present at subventral and subdorsal region of the anterior part. Head region separated by constriction (collar) surrounded by fine membrane. Large ‘S’ shaped holow dorsal tooth at the groove with a dorsal apophysis. Nerve ring present at 44%-57% to the anterior of pharynx. Pharynx cylindrical with double bulb. Anterior one smaller. Double bulb 46- 55 µm (i.e. 32%-36% of pharynx) in male and 57-62 µm (34%-37% of pharynx) in female. Ventral gland bulky and opens into a small slit at the anterior part. Cardia small, flattned. Body with moderate striation. Lateral alae extending full body length, bordered by larger dots and connected by cross-linking bars. No preclocal supplements in male. Male monorchic. Testis 17%-21% of the body length. Spicules smooth, equal and arcuate (40- 44 µm), 1-2 of anal body diameter. Gubernaculum short, 15-18 µm, distal end being broader than proximal end and corrugated. Female reproductive system didelphic with reflexed ovaries. Anterior ovary 73-137 µm is larger than Posterior ovary, 71-135 µm. Female reproductive system covers 48.6%-50.2% of total length. Tail conical, narrowed down with tapering end and finger like spinneret. abd is broader in male than female. Lateral alae absent from the tail end at 8-10 µm in male and 13-16 µm in female .

Habitat: Specimens were collected from sandy intertidal belt (99.18% sand, 0.67% silt and 0.15% clay) with 0.23% organic carbon content at Tajpur, Midnapore (East), West Bengal, India. The coastal area is flat and broad having gentle sloping. At the time of collection the temperature, salinity and pH of the sea water were 27.3°C, 23.7 ppt and

7.91 respectively.