Naineris Blainville, 1828

Blake, James A., 2017, Polychaeta Orbiniidae from Antarctica, the Southern Ocean, the Abyssal Pacific Ocean, and off South America, Zootaxa 4218 (1), pp. 1-145 : 94

Genus Naineris Blainville, 1828

Naineris Blainville, 1828 . Type-species: N. quadricuspida ( Fabricius, 1780) , by monotypy.

Anthostoma Schmarda, 1861 . Preoccupied. Type-species: Anthostoma ramosum Schmarda, 1861 (= Naineris laevigata ), designated by Pettibone (1957).

Lacydes Kinberg, 1866 . Preoccupied. Type-species: Lacydes havaicus Kinberg, 1866 (= Naineris laevigata ), by monotypy.

Polynaineris Pettibone, 1957 . Type-species: Naineris laevigata ( Grube, 1855) , by original designation.

Variant spellings. Naidonereis Malmgren, 1867 ; Nainereis Mesnil & Caullery, 1898 ; Naidoneris Webster & Benedict, 1887 .

Diagnosis. Prostomium rounded or truncate on anterior margin. Peristomium with 1–2 achaetous rings. Thorax with 12–30 or more segments; branchiae first present from setiger 2–23. Thoracic neuropodia with 0–2 postsetal lobes; no subpodial lobes. Thoracic neurosetae including capillaries, or capillaries mixed with blunt-tipped uncini, sometimes hooded, or uncini and subuluncini. Abdominal setae including capillaries and sometimes furcate setae in notopodia and capillaries and imbedded or protruding aciculae in neuropodia. Paired dorsal sensory organs present in some species.

Remarks. The following six species of Naineris were encountered and are treated in this paper:

N. setosa ( Verrill, 1900) ;

N. furcillata , new name for N. chilensis Carrasco, 1977 ; N. chilensis , new status for N. dendritica chilensis Hartmann-Schröder, 1965 ; N. grubei ( Gravier, 1908) ;

N. argentiniensis , n. sp.;

N. antarctica , n. sp.

The holotype vial of N. brevicephala Hartmann-Schröder, 1960 from Peru was examined and found to contain a syllid. Until the actual type specimen is located, N. brevicephala is best treated as incertae sedis.

Remarks on the genus Protoariciella Hartmann-Schröder, 1962a . Protoariciella was established for a small orbiniid that had two peristomial rings, and no distinct body regions, but has neuropodial uncini on a defined number of anterior setigers. The genus currently includes five species: P. uncinata Hartmann-Schröder, 1962a , the type species, from Peru and northern Chile ; P. heteroseta Hartmann-Schröder, 1962b from northern Chile; P. parauncinata Hartmann-Schröder, 1965 from northern Chile; P. subuluncinata Hartmann-Schröder, 1974 from West Africa ; and P. oligobranchia Hobson, 1976 from British Columbia. The genus appears to be confused because the type species, P. uncinata , was also reported to have thickened notopodial setae in the posteriormost segments ( Hartmann-Schröder, 1962a:134; 1965:131, fig. 156). None of the other four species are reported to have such setae in abdominal notopodia, yet this character was included in the original generic definition (Hartmann- Schröder, 1962a:133) and was used by Rullier (1972) and Fauchald (1977) to define and distinguish Protoariciella from related genera. Apart from a record of P. uncinata from Argentina by Elias et al. (2000), there have been few reports of any Protoariciella species in recent years. However, as part of a recent molecular analysis of some Orbiniidae by Bleidorn et al. (2009), specimens from Argentina collected by R. Elias and identified as P. uncinata were included in the analysis and were found to have the same genetic structure as Leodamas tribulosus from Chile. Some of Elias’s specimens were sent to me for examination in this study and the modified spines were clearly identical to those of L. tribulosus (see above). These are thus juveniles of L. tribulosus and were treated as such by Bleidorn et al. (2009). However, this does not demonstrate that P. uncinata of Hartmann-Schröder (1962a) is the same species.

To add to the confusion, Naineris antarctica n. sp. has two peristomial rings, but otherwise differs considerably from all of the previously described species of Protoariciella , found in the Antarctic collections. This new species has heavy spines in all abdominal notopodia (see below), but also has a distinct thorax and abdomen.

Given the small size of the various species of Protoariciella (all less than 10 mm) described thus far and the fact that two achaetous peristomial segments are characteristic of larval and postlarval stages of different species of Naineris and Leodamas tribulosus , it seems likely that the five species of Protoariciella are all juveniles of other orbiniids. There is no information to indicate that any of Hartmann-Schröder’s specimens were sexually mature. Apart from the double nature of the peristomial rings, the new Antarctic species agrees with the definition of Naineris to which it is here assigned. Assuming that Protoariciella species are indeed juveniles of other larger species, then the genus would be a synonym of either Leodamas or Naineris depending on the placement of the type-species P. uncinata . Both P. uncinata and P. parauncinata have bifid neuropodial uncini and may be juveniles of N. grubei or possibly L. tribulosus , whereas P. heteroseta , with neuropodial uncini that have entire tips might be a juvenile of N. chilensis . Apart from the specimens identified as P. uncinata by Elias et al. (2000) from Argentina and demonstrated to be juveniles of L. tribulosus , no adult specimens resembling the three South American species of Protoariciella were encountered in the present study.