Pistella Hartmann-Schröder, 1996

Nogueira, João Miguel Matos, Hutchings, Pat & Carrerette, Orlemir, 2015, Terebellidae (Annelida, Terebelliformia) from Lizard Island, Great Barrier Reef, Australia, Zootaxa 4019 (1), pp. 484-576 : 531-534

Genus Pistella Hartmann-Schröder, 1996

Pistella Hartmann-Schröder 1996: 520 .

Type-species. Scionella lornensis Pearson, 1969 , by monotypy.

Diagnosis. Transverse prostomium attached to dorsal surface of upper lip; basal part without eyespots; distal part shelf-like. Buccal tentacles all similar, but of different lengths, usually shorter than body length. Peristomium forming lips; hood-like upper lip, usually as wide as long; small, swollen lower lip, restricted to oral area. Segment 1 reduced dorsally, frequently with paired ventral lobes lateral to mouth, connected to each other by low lobe marginal to mouth. Segment 2 with paired ventro-lateral lobes connected to each other by protruding mid-ventral crest. Segment 3 with relatively short lateral lobes. Paired dorso-lateral plumous branchiae present on segment 2, single pair. Anterior segments with glandular, rectangular to trapezoidal, smooth to slightly corrugated mid-ventral shields; shields typically divided in two parts, anterior part white, posterior part bright red. Short and conical notopodia beginning from segment 4, typically extending for 17 segments, until segment 20. Winged notochaetae in both rows, wings always conspicuous, frequently broadly-winged, as broad as width of shaft or broader. Neuropodia present from segment 5, as low ridges until termination of notopodia, as raised pinnules thereafter. Neurochaetae throughout as short-handled avicular uncini, arranged in partial to completely intercalated double rows from segment 11 until termination of notopodia; uncini with dorsal button at mid-length of base, conspicuous at least until termination of notopodia, and crest with several transverse rows of secondary teeth. Nephridial and genital papillae usually present on segments 3 and 6–7, respectively, the latter posterior and dorsal to notopodia. Pygidium papillate.

Remarks. Pistella was erected by Hartmann-Schröder (1996) to accommodate species previously considered as belonging to Pista by Safronova (1988) in her partial revision of the type species of the genus. Pistella has a single pair of branchiae and short-handled uncini throughout ( Hartmann-Schröder 1996). Safronova (1988) transferred Scionella lornensis Pearson, 1969 to Pista , subsequently Hartmann-Schröder (1996) moved it into her new genus Pistella and designated it as the type species.

More recently, Jirkov et al. (2001) synonymized Pistella lornensis with Pista cristata ( Müller, 1776) , based on a reinterpretation of the original description of the latter species in regards to the number of pairs of branchiae present, a single pair instead of two pairs, as considered by Malmgren (1866) in the original description of Pista . That synonymy, however, requires that all species currently assigned to Pista should be transferred to a new, still undescribed genus, due to the presence of long-handled uncini on anterior segments, which are absent in P. cristata sensu Jirkov et al. (2001) . As both forms, with single pair of branchiae and short-handled uncini throughout, and with two pairs of branchiae and long-handled uncini on anterior segments co-occur in the type locality of P. cristata , we prefer to follow Malmgren´s interpretation of P. cristata and consider both Pista and Pistella as valid genera.

This genus has never been formally reported from Australian waters, but Pista anthela Hutchings & Glasby (1990) matches the diagnosis above, with regards to the number of pairs of branchiae and the uncinial morphology, and, therefore, is herein transferred to Pistella . In the material from Lizard Island a second species of Pistella was found, described below.