Polycirrus tentaculatus
Creators: name: Glasby, Christopher J.
name: Hutchings, Pat
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Animalia
Annelida
Polychaeta
Terebellida
Terebellidae
Polycirrus
Polycirrus tentaculatus

description: Polycirrus tentaculatus (Hartmann-Schröder, 1960)
Fig. 58a–e
Pseudoampharete tentaculata Hartmann-Schröder, 1960: 39–41, figs 84–88.
Polycirrus tentaculatus.— Holthe, 1986a: 171.
Type locality. North Peru, intertidal in rock pool.
Material examined. Holotype ZMH-P15400, Bei Cancas, North Peru, coll. 13.ix.1950.
Description. Coded from the original description and examination by PH of holotype at ZMH. Holotype 12 mm long, 1.5 mm wide with 41 segments.
Dorsum anteriorly smooth (Fig. 55a). Venter anteriorly with mid-ventral groove and discrete ventro-lateral pads; pads incised by transverse grooves, extending from segment 2. Mid-ventral groove from segment 2 (Fig. 58b). Sex female.
Buccal tentacles of three types: (1) leaf-shaped, deeply furrowed, (2) cylindrical, thickened distally and distinctly grooved and (3) cylindrical, uniformly thin and weakly grooved, all arising at junction between prostomium and upper lip. Prostomial ridge distinctly curved, extending laterally along anterodorsal base of upper lip. Upper lip trefoiled with lateral blindly ending enclosed diverticulae, margin of medial lobe convoluted; oral surface glandular and ciliated. Inner lower lip not described; outer lower lip flat, shield-like, oblong, wider than long, ridged and grooved longitudinally, extending posteriorly to segment 2. Achaetous segments Achaetous segments visible entirely as distinct rings (Fig. 58a, b).
Notochaetigerous segments 45, extending to segment 47. Notopodia more-or-less rectangular, lobes triangular, postchaetal (Fig. 58c), posterior notopodia cone-shaped. Notochaetae within a chaetiger consisting of two types: smooth, narrowly winged, wings striated; tips appears to be hooked, perhaps damaged, uniformly tapered; secondary notochaetae in all chaetigers pinnate (Fig. 58d). Neurochaetae beginning on segment 7. Uncini arranged in slightly curved row with about 43 within a single row. Uncini with short neck and straight to convex base (Type 1), teeth above main fang arranged in double transverse series (MF:1:6–8) enlarged median tooth above main fang present, subrostral process absent (hook-shaped extension on the unicinus base assumed to be posterior anchor rod common to all Polycirrus) (Fig. 58e).
Nephridial papillae, present, rounded. Pygidium smooth, no appendages.
Comments. The above description is coded from the type descrition. Hartmann-Schröder (1960) interpreted the tentacles on the lateral part of the upper lip as possible branchiae; also she thought that an enlarged tentacle represented a palp—hence the view that the animal belonged to Ampharetidae; she corrected herself in a later publication (Hartmann-Schröder, 1962) transferring the genus to Polycirrinae. We have compared the type material of P. multisetigerous (from Chile) with the type description of Pseudoampharete tentaculatus (from northern Peru) and found the two species to be very similar, differing only in the following features: anterior dorsum is tessellated in P. multisetigerous and smooth in P. tentaculatus, the mid-ventral groove begins from segment 2 in P. multisetigerous (segment 1 in P. tentaculatus), the upper lip is trefoil shaped in both species, but with small lateral wing-like lobes in P. multisetigerous and lateral blindly ending closed diverticulae in P. tentaculatus, the oral surface of the upper lip lacks grooves leading to the mouth in P. multisetigerous but the grooves are present in P. tentaculatus, the outer lower lip is subtriangular and elevated in P. multisetigerous but oblong and longitudinally grooved in P. tentaculatus. There are no significant differences in the more reliable characters, viz. number of notochaetigerous segments, notochaetae and the segment on which the uncini start. However, we propose maintaining the two species as separate entities, but the hypothesis that they are conspecific should be tested when more material becomes available of each species, including mature specimens to allow comparison of the form and arrangment of nephridial papillae.
description: Published as part of Glasby, Christopher J. & Hutchings, Pat, 2014, Revision of the taxonomy of Polycirrus Grube, 1850 (Annelida: Terebellida: Polycirridae), pp. 1-117 in Zootaxa 3877 (1) on pages 102-104, DOI: 10.11646/zootaxa.3877.1.1, http://zenodo.org/record/4948375