Family Marimermithidae

Revised 02/04/22

Classification:

  Enoplea

    Dorylaimia

     Mermithida

      Mermithina

        Mermithoidea

       

Marimermithidae Rubzov & Platonova, 1974

Nematode parasites of marine invertebrates.

Rubzov and Platonova (1974) erected the family Marimermithidae including Marimermis, Trophomera Rubzov & Platonova, 1974 and Thalassonema Ward, 1933, which were the only genera known at the time. Later, the genera Ananus Rubzov, 1977, Acronema Rubzov, 1978 and Australonema Tchesunov & Spiridonov, 1985 were described and included in Marimermithidae  (Rubzov, 1985; Tchesunov & Spiridonov, 1985).

• Marimermithidae is a small family of marine nematodes.
• Widespread and have been recorded in south-western Indian Ocean, north and south Atlantic and in the north and south Pacific.
• Occur at different depths all the way from the tidal zone, down to a depth of 5.2 km.
• Not much of their life history is known, but probably similar to tanother rare group of marine parasitic nematodes of the family Benthimermithidae
• Marimermithids live as parasites, during their juvenile stages, of aquatic invertebrates, including echiuroids, priapulids, polychaetes, gastropods, sea urchins, starfish and basket stars. As adults they are free-living, and it is unknown if they feed at all during this stage, or if they like the Benthimermithids consume nutrients accumulated during the parasitizing stage (Miljutin, 2014).
• Rubzov (1980, 1985)proposed a new order, Marimermithida Rubzov,1980, to include the genera Benthimermis Petter, 1980, Abos Rubzov, 1980, and Adenodelphis Petter, 1983.  These genera differ from each other in significant morphological features. Benthimermis, unlike Marimermis and other species, has an alimentary tract that includes a trophosome, consisting of large cells and with only a thin capillary lumen.  The trophosome has very weak apparent connections to the esophagus and rectum.

Relationships between Marimermithidae and Benthimermithidae:

• Originally, Marimermis, the type genus of the family Marimermithidae, and Trophomera (= Benthimermis Petter, 1980), the type genus of the family Benthimermithidae, were described together and placed in the same family Marimermithidae (Rubtsov & Platonova, 1974).
• Molecular data support morphology-based conclusions that the organisms represent two evolutionary independent lineages.

Ref: Westerman et al (2021)

References:

Rubtsov, I. A. (1985). A new species of the genus Thalassonema (Nematoda). Zoologicheskii Zhurnal, 64, 446–448.

Rubzov and Platonova (1974) erected the new family Marimermithidae including Marimermis together  with two other genera, Trophomera Rubzov & Platonova, 1974 and Thalassonema Ward, 1933, which were the only genera known at the time.

Miljutin, D. (2014). 7.10 Order Marimermithida Rubtsov 1980, emend. Tchesunov 1995. In. Schmidt-Rhaesa, A. (Ed.), Nematoda (pp. 345–350). Walter de Gruyter.

Tchesunov, A. V., & Spiridonov, S. E. (1985). Australonema eulagiscae gen. et. sp. n. (Nematoda, Marimermithida) – a parasite of a polychaete from Antarctic. Vestnik Zoologii, 2, 16–21

Westerman, R., de Moura Neves, B., Ahmed, M. et al. (2021) Aborjinia corallicola sp. n., a new nematode species (Nematoda: Marimermithidae) associated with the bamboo coral Acanella arbuscula (Johnson). Syst Parasitol 98, 559–579