Life Cycle: “The life cycle is indirect involving an arthropod intermediate host. Eggs once passed with droppings hatch and are swallowed by intermediate hosts which are water crustaceans, Daphnia pulex, and Gammarus pulex. The final host acquires the infection following ingestion of the infected intermediate host. Immediately following ingestion, the male and female parasites migrate to the proventriculus where they embed in the glands. After copulation males migrate to the lumen and die” (Kamil et al., 2011).
Male: Body length 3-6 mm, body width 0.14-0.2 mm. Longitudinal rows of cuticular spines present. Anterior end with lateral cuticular appendages. Buccal capsule 0.02-0.03 mm long and 0.009-0.013 mm in diameter. Cervical papillae asymmetrical, 0.14-0.16 mm from anterior end. Oesophagus 0.79-1.44 mm long with muscular part 0.32-0.45 mm and glandular 0.47-0.76 mm long. Nerve ring 0.18-0.245 mm and excretory pore 0.225-0.27 mm from anterior end. Long spicule 0.28-0.49 mm long, short spicule 0.09-0.2 mm long. Tail 0.21-0.265 mm long with conical appendage about 0.01 mm long and provided with spines.
Female: Body length 1.58-6.0 mm, maximum body width 0.96-3.6 mm. Buccal capsule 0.018-0.023 mm long. Oesophagus 1.2-1.49 mm long, with muscular part 0.21-0.315 mm long and glandular part 0.97-1.23 mm long. Cervical papillae 0.11 mm and nerve ring 0.13-0.185 mm from anterior end. Tail 0.07-0.175 mm long. Vulva 0.1-0.41 mm from posterior end. Eggs 0.03-0.06 x 0.025-0.035 mm.
Sources: Rysavy, B. and Ryzhikov, K.M. 1978. Helminths of Fish-Eating Birds of the Palaearctic Region: Nematoda. p. 216.
Kamil, S.A., Darzi, M.M., Mir, M.S., Shah, S.A., Shah, S.N. and Khan, F.A. 2011. Tetrameres Fissispina Infection in Ducks from Bandipora Area of Kashmir Valley. Israel Journal of Veterinary Medicine. Vol. 66, No. 2.