Janita Saint-Joseph, 1894

Ten Hove, Harry A. & Kupriyanova, Elena K., 2009, Taxonomy of Serpulidae (Annelida, Polychaeta): The state of affairs, Zootaxa 2036, pp. 1-126 : 55-57

17. Janita Saint-Joseph, 1894

( Fig. 24)

Type-species: Omphalopoma spinosa Langerhans, 1884 , = junior synonym of Serpula fimbriata delle Chiaje, 1822 Number of species: 1

Tube white, sub-circular in cross-section, with 5 longitudinal winding ridges. Granular overlay absent. Operculum bell-shaped, ending in simple thick brown concave endplate; opercular base surrounded by three fleshy processes, one triangular and two rounded ones, not unlike those figured for Crucigera zygophora by ten Hove & Jansen-Jacobs (1984 fig. 9C). Peduncle cylindrical, slightly compressed dorso-ventrally and wrinkled; inserted below and between first and second normal radiole (below second in larger specimens). Pseudoperculum absent. Arrangement of radioles short pectinate, up to 12 radioles per lobe. Inter-radiolar membrane and stylodes absent. Branchial eyes present, reported as stalked eyes at base of pinnules by Langerhans (1884 fig. 45a). Mouth palps present. 7 thoracic chaetigerous segments. Collar pentalobate, medioventral lobe divided by deep median and two shallow incisions. Tonguelets absent. Thoracic membranes short, ending at second thoracic chaetiger. Collar chaetae of Spirobranchus type ( Fig. 24B), acicular and limbate. Apomatus chaetae present ( Fig. 24C). Thoracic uncini saw-shaped with up to 16 teeth, anterior peg blunt, questionably gouged ( Fig. 24E). Triangular depression absent. Anterior abdominal uncini saw-shaped, posterior rasp-shaped ( Fig. 24F), with approximately 13 teeth in profile, 3–5 teeth per row. Abdominal chaetae flat narrow geniculate, with a more or less crenulated edge to the blade ( Fig. 24D). Achaetous anterior abdominal zone very short or absent. Long posterior capillary chaetae absent. Posterior glandular pad present.

Remarks. The genus Janita was erected by Saint-Joseph for Omphalopoma spinosa Langerhans, 1884 , which is a junior synonym of Serpula fimbriata delle Chiaje, 1822 (see e.g., Fauchald, 1977: 144, Lommerzheim 1979: 157). There was a considerable confusion about generic attribution of this species, generally it has been attributed to Omphalopomopsis . Zibrowius (1972b) points out that the distinction between Janita and Omphalopomopsis is justified due to having very different opercula: O. langerhansi has a simple globular operculum with a shallow concave calcareous endplate, J. fimbriata has a more complex operculum with a deeply cupped chitinous endplate, which has a horny talon into the fleshy opercular ampulla ( Imajima, 1979).

It should be noted that Rioja (1923) and Fauvel (1927) mentioned both “ Spirobranchus ” type and acicular collar chaetae for Janita fimbriata (as Omphalopomopsis ); ( Zibrowius (1968a) on the other hand regarded the “acicular” chaetae as misinterpretation of “ Spirobranchus ” type, observed from the back (not in lateral view). Martín (1989) assumed that specimens with acicular collar chaetae and those with “ Spirobranchus ” type chaetae belong to different taxa. Ben-Eliahu & Fiege (1996) mentioned specimens with one or the other type of collar chaetae from a single population of what they regard to be J. fimbriata ; ten Hove (in Ben-Eliahu & Fiege 1996) mentioned a specimen with both types. The phenomenon merits further attention.

The monotypic genus is distributed in the (sub) tropical Atlantic, Mediterranean ( Zibrowius 1972b, 1973b, Bianchi 1981, Bianchi et al. 1984), and Indo-West Pacific ( Imajima & ten Hove, 1984, 1986, ten Hove 1994). See also remarks following Omphalopomopsis .

Janita fimbriata (delle Chiaje, 1822), (sub)tropical Atlantic, Mediterranean, Indo-West Pacific.