Naineris sp.

Álvarez, Ricardo & Budaeva, Nataliya, 2023, How complex is the Naineris setosa species complex? First integrative study of a presumed cosmopolitan and invasive annelid (Sedentaria: Orbiniidae), Zootaxa 5375 (3), pp. 349-378 : 371-372

Naineris sp.

( Fig. 12 )

Material examined. USA, California. SERC 252007 (DNA voucher Ns46, + 1 spm), SERC 252013 (DNA voucher Ns47, + 2 spms), SERC 251805 (1 spm), SERC 251985 (1 spm, 1 for SEM), SERC 252000 (2 spms), LACM-AHF: DNA vouchers Ns33, Ns34, Ns35.

Description. Small specimens, presumably juveniles ( Fig. 12A ). Color in alcohol light tan.Thorax and abdomen distinct. Prostomium anteriorly rounded ( Fig. 12A ); eyespots not discernible; nuchal organs present. Peristomium as 1–2 achaetous rings ( Fig. 12A ); mouth opening located ventrally; proboscis not everted.

Branchiae from chaetiger 6 ( Fig. 12A ), elongate from first pair. Paired dorsal sensory organs between branchial bases, oval-shaped ( Fig. 12B, C ). Dorsal crest as ciliary bands from first thoracic segment, straight ( Fig. 12B ).

Thorax dorsoventrally flattened. Parapodia biramous. Thoracic notopodial and neuropodial lobes lanceolate. Abdominal notopodial and neuropodial lobes triangular.

Thoracic notochaetae with crenulated capillaries only. Abdominal notochaetae including capillaries and furcate chaetae ( Fig. 12D ); furcate chaetae with unequal tynes and thin needles between; shaft with several transversal rows of 5–7 barbs. Thoracic neurochaetae with capillaries only. Abdominal neurochaetae with capillaries and 1–2 acute acicular spines ( Fig. 12E ).

Pygidium with terminal anus, bearing anal cirri, presumably four cirri.

Remarks. Based on molecular data, the examined specimens represent an undescribed species. All specimens were of small size, presumably juveniles. The species is unique in having dorsal ciliary bands from the first thoracic segments. However, the species is not formally named here due to a lack of detailed information on the adult definitive morphological characters.

Figures

FIGURE 12. Naineris sp. examined under SEM (SERC 252000): (A) Anterior end, dorsal view; (B) Thoracic segments, dorsal view; (C) Cilia in dorsal organs; (D) Furcate chaetae in abdominal segment, lateral view; (E) Acicular spines in abdominal segments. bq—branchia, c—dorsal organ cilia, cb—ciliary band, cc—crenulated capillary chaeta, do—dorsal organ, fc—furcate chaeta, NoL—notopodial lobe, pe—peristomium, pr—prostomium. Scale bars; (A): 100 μm; (B): 20 μm; (C): 10 μm; (D–E): 2 μm.