Tetranchyroderma bronchostylus sp. nov., the first known gastrotrich (Gastrotricha) with a sclerotic canal in the caudal organ

Abstract

A new species of Tetranchyroderma (Macrodasyida: Gastrotricha) is described from coarse sediments at 9 m depth at Capron Shoals, Florida. Tetranchyroderma bronchostylus sp. nov. is distinguished primarily by the presence of a sclerotic canal within the accessory caudal organ, and represents the first species of Tetranchyroderma described with such a feature. The following combination of characters further distinguish this species from its congeners: an oral hood with a scalloped margin, paired cephalic tentacles, paired sensorial organs, a pentancrous cuticle, three pairs of dorsolateral adhesive tubes, one pair of ventrolateral adhesive tubes in the pharyngeal region and up to 11 pairs of ventrolateral tubes in the trunk region, and one pair of lateral adhesive tubes close to the paired caudal pedicles.