Caulleriella Chamberlin, 1919

Blake, James A., 2018, Bitentaculate Cirratulidae (Annelida, Polychaeta) collected chiefly during cruises of the R / V Anton Bruun, USNS Eltanin, USCG Glacier, R / V Hero, RVIB Nathaniel B. Palmer, and R / V Polarstern from the Southern Ocean, Antarctica, and off Western South America, Zootaxa 4537 (1), pp. 1-130 : 39-40

Genus Caulleriella Chamberlin, 1919

Type species: Cirratulus viridis Langerhans, 1881 , original designation by Chamberlin 1919.

Diagnosis. Prostomium elongate; peristomium elongated to short, dorsal tentacles usually beginning anterior to setiger 1. Middle body segments not beaded; parapodia with noto- and neuropodia widely separated from one another laterally. Modified setae including bidentate, crotchet-like hooks, not arranged into modified cinctures.

Remarks. Blake (1996) revised the definition of Caulleriella to include bitentaculate cirratulid species having only bidentate, crotchet-like hooks and with the noto- and neuropodia widely separated from one another.

The genera Caulleriella and Tharyx are similar and separated with difficulty. Both genera have modified spines that are more or less bidentate. In Caulleriella these spines have two well-developed teeth, both sharply pointed and sometimes hooded. Species of Tharyx , on the other hand, have poorly developed teeth on the hooks; these are usually reduced to rounded knobs or stumps, or not apparent at all. Caulleriella and Tharyx also differ considerably in the manner in which the setal fascicles arise along the body. In species of Caulleriella , there is a wide lateral gap between the noto- and neuropodial setal fascicles. This separation of the fascicles of noto- and neurosetae is so wide that, in some species in cross section, the setae occur in four separate corners of the body. In contrast, the points of origin of noto- and neurosetae of Tharyx species are typically close together or, if separated, the gap is not wide.

Hartmann-Schröder & Rosenfeldt (1989, 1990) reported four species of Caulleriella from Antarctica. Of these, only C. aff. zetlandica is likely a true Caulleriella ( Hartmann-Schröder & Rosenfeldt, 1989) and is here referred to C. eltaninae n. sp. (see below). Three other species described by these authors do not belong to Caulleriella and are referred elsewhere. Caulleriella bransfieldensis Hartmann-Schröder & Rosenfeldt, 1989 is referred to Chaetozone because it has simple spines formed into partial cinctures in posterior setigers. Caulleriella homosetosa Hartmann-Schröder & Rosenfeldt, 1989 is also referred to Chaetozone because it has simple, blunt-tipped spines in posterior noto- and neuropodia that are organized into partial cinctures. Caulleriella obtusa Hartmann-Schröder & Rosenfeldt, 1990 is referred to Tharyx because it has blunt, knobby-tipped spines and the rami of the parapodia are not widely separated. Types of these species were examined during a brief visit to the ZMH in 2002; numerous additional specimens have been identified during this study, thus adding to details about these species.

Four new species from the Antarctic collections that agree with the definition of Caulleriella provided by Blake (1996) have been discovered as part of this study: Caulleriella eltaninae n. sp., C. fucata n. sp., C. kacyae n. sp., and C. fimbriata n. sp. These, together with C. antarctica previously described by Hartman (1978) from the Weddell Sea brings the total to five species of this genus in Antarctic waters. Two additional new species have been discovered from off western South America: C. ecuadoriana n. sp. from shallow water off Ecuador and C. suroestense n. sp. from the Juan Fernandez Islands off Chile. In addition, the holotype of C. magnaoculata described from off Peru by Hartmann-Schröder (1962) has been examined and redescribed.