Synonchus		Contents		Rev: 03/29/2025
		Classification		Biology and Ecology
		Morphology and Anatomy		Life Cycle
Return to Synonchus Menu				Ecosystem Functions and Services
		Distribution		Management
Return to Leptosomatidae Menu		Feeding		References
		Go to Nemaplex Main Menu		Go to Dictionary of Terminology

Classification:

Enoplea

  Enoplia
        Enoplida

            Ironina

                Ironoidea

                     Leptosomatidae

Synonchinae

Synonchus  Cobb, 1893

Type species of the genus: Synonchus fasciculatus Cobb, 1893

Note: The genus name honors Tatyana Alekseevna Synonchus, a Russian nematologist who studied the family Leptosomatidae intensively.

    Synonyms:

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Morphology and Anatomy:

 Genus Synonchus differs from other known Synonchinae by:

•  the tail shape - conical anteriorly, filiform posteriorly
•  division of pharyngostome into 2 distinct parts,
• one dorsal tooth in the anterior part of pharyngostome,
• 6 cuticular supports and microonchia in the posterior part of pharyngostome.

Characteristics:

• Very large nematodes.
• Cephalic capsule relatively long, interlobular grooves wide. Three well-developed lips.
• Amphideal fovea large, pocket-shaped, located in lateral grooves.
• Six small inner labial papillae (2 on each lip); six outer labial setae and four cephalic setae in one circle, relatively equal in length. Short post-amphideal setae present.
• Cheilostome with three mandibular ridges, odontia present.
• Single dorsal onchium in the anterior part of pharyngostome. The posterior part of pharyngostome is reinforced with 6 cuticular thickeningss (two on each of the dorsal and two ventrosublateral sectors), with contains microonchia.
• Tail conical anteriorly, filiform posteriorly.

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Distribution:

Deep-sea nematodes; species of the family Leptosomatidae are reporterd to occur frequently in macrobenthic samples from the North-Western Pacific ocean. Reported at depths of 3300 to 4500 meters below sea level in the Kuril-Kamchatka Trench and adjacent areas.

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Feeding:

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Biology and Ecology:

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Life Cycle:

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Ecosystem Functions and Services:

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Management:

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References:

Mordukhovich, V.V., Semenchenko, A.A., Fadeeva, N.P., Zograf, J.K. 2019. One new genus and two new free-living deep-sea nematode species with discussion of phylogeny of the family Leptosomatidae Filipjev, 1916. Progress in Oceanography, 178: doi.org/10.1016/j.pocean.2019.102160

Synonchus, T.A., 1970. On the Taxonomy of the Leptosomatidae (Nematoda) of the Mediterranean Sea and of the Adjacent Waters of the Atlantic [O sistematike Leptosomatidae (Nematoda) Sredizemnogo Morya i prilezhashchikh vod Atlantiki]. Zoologicheskii Zhurnal 49:1298-1305.

Synonchus, T.A., 1976. Lower Enoplida (free-living marine nematodes) of the seas of the USSR (in Russian). Issledovaniya Fauny Morei (Nematody i ikh rol' v meiobentose) 15:3-164.

Synonchus, T.A., 1979. Structure of the head end and system of the subfamily Synonchinae (Nematoda, Enoplida, Leptosomatidae) (Struktura golovnogo kontsa i sistema podsemeistva Synonchinae (Nematoda, Enoplida, Leptosomatidae)). Zoologicheskii Zhurnal 58 1117-1129.

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Copyright © 1999 by Howard Ferris.
Revised: March 29, 2025.