Serrula Schockaert & Curini-Galletti & Ridder & Volonterio & Artois 2009, SP. NOV.
Creators: name: Schockaert, Ernest R.
name: Curini-Galletti, Marco
name: Ridder, Wouter De
name: Volonterio, Odile
name: Artois, Tom
Publisher: name: Zenodo
Year: 2009
Subjects: Biodiversity
Taxonomy
Animalia
Platyhelminthes
Rhabditophora
Seriata
Meidiamidae
Serrula

description: SERRULA ACUTA SP. NOV.
Serrula acuta: species of Serrula with a single seminal vesicle?; slender pointed needles that are 25-Mm long, and are 6-Mm wide at the base. No data on the living animal.
Serrula acuta: same locality as S. maxillaria.
Material studied: Drawings from the living animals, except for S. acuta. One whole mount of each species (designated as holotypes, QM G 230108–230111). Sections of one individual of S. byronensis of very poor quality, and without relevant information (except the epidermis) (UH 393).
Etymology: The genus name refers to the serrate end of the needles in two of the species (Latin serrula: little saw). The species epithet of S. byronensis refers to the place where it has been found; that of S. concharum refers to the co-occurrence with many shells (Latin concha: shell); the needles of S. maxillaria show some resemblance to the maxillae of crustaceans; the needles of S. acuta are very slender and pointed (Latin acuta: pointed).
Description: These four species are described from only one living individual of each species, and from the whole mounts. Therefore, our knowledge of a number of important characters is lacking. Nevertheless, we consider it worthwhile to describe them, hoping that more abundant material may be found in the future.
The four species are relatively small: only about 1-mm long. They have the usual anterior sensory bristles, but also have long bristles at the caudal end. Serrula byron also has prominent adhesive papillae (Figs 13, 14). The precerebral gut diverticle reaches far in front of the statocyst in S. concharum, whereas it ends roughly above the statocyst in S. byronensis and S. maxillaria (and is unknown in S. acuta). Cnidocysts were seen in the anterior part of the gut in S. maxillaria.
The globular and ventrally directed pharynx is placed at the first quarter of the body; the ovaries, located anterior to the pharynx, are preceded by a single pair of testes. All vitellarian follicles are behind the pharynx, and the posteriormost follicles are found in front of the copulatory bursa in S. byronensis, and in front of the copulatory organ in the other species. The female pore is located at some distance behind the seminal vesicle (Fig. 14). The copulatory organ is directed forwards, with a small prostate vesicle on which the two needles are attached. Serrula concharum has a pair of seminal vesicles; the other species have an unpaired seminal vesicle. Only in S. byron has a prepenial copulatory bursa been observed, with a vagina just in front of the copulatory organ. We could not determine whether the vagina and the male pore are combined or not. As far as the whole mount reveals, S. acuta has a single seminal vesicle, whereas a copulatory bursa is absent. Without sections, it cannot be said if a genitointestinal connection or a resorbing bursa is present.
The hard parts of the copulatory organ (Fig. 15) consist of two spines that we interpret as the equivalent of the needles in the male atrium of the other representatives of Meidiamidae. Except in S. acuta, each of the two needles sits on a base, evidently formed by two muscles that ‘flank’ the prostate vesicle at either side. Because of the lack of sections, the hypothesis that these bases are muscles is yet to be confirmed. The form and size of the needles are given in the diagnoses.
description: Published as part of Schockaert, Ernest R., Curini-Galletti, Marco, Ridder, Wouter De, Volonterio, Odile & Artois, Tom, 2009, A new family of lithophoran Proseriata (Platyhelminthes), with the description of seven new species from the Indo-Pacific and South America, and the proposal of three new genera, pp. 759-773 in Zoological Journal of the Linnean Society 155 (4) on pages 767-768, DOI: 10.1111/j.1096-3642.2008.00463.x, http://zenodo.org/record/4635038