Rev 11/21/2025
Enoplea
Dorylaimia
Mermithida
Mermithina
Mermithoidea
Benthhimermithidae
Trophomera Rubtsov & Platonova, 1974
Type species of the genus: Trophomera iturupiensis Rubtsov & Platonova, 1974
Benthimermis now considered a junior synonym of Trophomera (Miltjutin, 2006).
Rubzov and Platonova (1974) erected the new family Marimermithidae to include Trophomera and two other genera, Trophomera Rubzov & Platonova, 1974 and Thalassonema Ward, 1933, which were the only genera known at the time.
Most species of Trophomera have been described from very few free-living adult specimens, either males or females, and both sexes are known in only a few species (Trophomera australis (Petter, 1983) and T. petterae (Miljutin, 2004)). Some species descriptions have been based on a single specimen. The size range of known benthimermithids varies from less than 1 mm to 17 cm; however, the body length of most species is sin the range of 1- 15 mm. Miljutin (2004, 2011)
Female:
Ref: Miljutin and Tchesunov, 2001.
Benthimermithids are quite rare and usually comprise less than 1% of nematode assemblages (Miljutin, 2011). As of 2025, around 50 species of Trophomera have been described. They have been found from the Arctic to Antarctic and throughout the Atlantic and the Indian oceans (Miljutin 2004). Tey are widespread in the oceans of the world and their known habitat will be extended as new deep-sea areas are studied.
Species are described from bottom sediments of the deep-sea off the coast of Norway at depths of 2668-2904 m (Miljutin and Tchesunov, 2001). Other species are described from the South Indian Ocean.
Food Sources and Feeding strategies for the genus Trophomera
Juveniles parasitic in marine invertebrates, adults apparenly not feeding. The intra-cellular inclusions and shrinkage of the trophosome, together with degradation of the reproductive organs, suggest that the trophosome functions to store nutrients that are expended during the free-living adult stage in sediments (Miljutin and Tchesunov, 2001).
Like the mermithids of fresh-water and soil environments (Order Mermithida), the larval stages of benthimermithids parasitise the body cavities and internal organs of invertebrate hosts, including polychaetes, priapulids, various crustaceans, holothuroids and free-living nematodes. Adult or late larval stages leave the host and enter a nonparasitic phase in which they reproduce but, based on their modified digestive system and lack of a mouth, apparently do not feed. So, larval stages parasitize benthic invertebrates, while non-feeding adult stages reproduce in benthic sediment (Miljutin and Tchesunov, 2001).
Miljutin, D.M. 2011. Deep-sea parasitic nematodes of the genus Trophomera Rubtsov et Platonova, 1974 (Benthimermithidae) from the Equatorial Atlantic, with the descriptions of two new species. Helgol Mar Res 65:245-256
Miljutin, D.M. 2006. The genus Trophomera Rubtsov & Platonova, 1974 with description of T. litoralis sp. n. (Nematoda: Benthimermithidae) from the tidal zone of the Kuril Archipelago and proposal of Benthimermis Petter, 1980 as a junior synonym. Nematology 8:411-423, https://doi.org/10.1163/156854106778493457
Miljutin, D.M. and Tchesunov, A.V. 2001. On the histological anatomy of Benthimermis megala Petter, 1987, a giant nematode from the Norwegian deep-sea (Nematoda: Benthimermithidae). Nematology 3:491-502.
Petter A-J. 1980. Une nouvelle famille de Nematodes parasites dde invertebrates marins, les Benthimermithidae. Annales de Parasitologie Humaine et Comparee 55: 209-224.
Pettier, A.J. 1983. Quelques nouvelles especes du genre Benthimermis Petter, 1980 (Benthimermithidae: Nematoda) du Sud de l'Océan Indien. Syst. Parasitol. 5:1-15.
Platonova, T. A., & Galtsova, V. V. (1976). Nematodes and their role in the meiobenthos. Akademiya Nauk.
Rubtsov, I. A., & Platonova, T. A. (1974). A new family of marine parasitic nematodes. Zoologicheskii Zhurnal, 53, 1445-1458.