A new species of Dondersiidae (Mollusca, Solenogastres) associated with a hydroid, with insights into the trophic ecology of Solenogastres

We describe a new species of Solenogastres in the family Dondersiidae, Nematomenia quattriniae sp. nov ., using an integrative taxonomic approach. The species is characterized by a slender, light-yellow body with a scaly appearance and dorsal keel, prominent anterior pedal glands, a dorsal foregut gland, a single dorso-terminal sensory organ, and the presence of seminal receptacles and seminal vesicles. Specimens were collected from a bathyal site (581 m depth) on the continental slope off Louisiana (USA) associated with the hydrozoan Acryptolaria abies (Allman, 1877), which displayed signs of an active defense response. This study sheds light on the trophic ecology of solenogasters and highlights the continued discovery of novel biodiversity and predator-prey interactions in deep-sea ecosystems.