Naineris chilensis Hartmann-Schröder, 1965,

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 : 98-101

Naineris chilensis Hartmann-Schröder, 1965 , New Status

Figures 46–47

Naineris dendritica chilensis Hartmann-Schröder, 1965: 195 –197, figs. 179–180; Rozbaczylo 1985: 130.

Material examined. Ecuador, Anton Bruun Sta. 66-70 (1, USNM 60641 ), 8–9 m; 3 juveniles ( USNM 60637 ) .— Peru, South of Callao, Anton Bruun Sta. 65-215, shallow subtidal ( USNM 60640 ) .— Chile, Arica Province , Aricia , 18°29′33″S, 70°19′17″W, intertidal shale, coll. Eric Guiler, Papudo Corvette sta. N 17, 26–28 Feb 1955 (1, LACM- AHF Poly 5021) ; Chile, Puerto Aguirre , coll. 21 Jul 1958, 10 m, holotype of Naineris dendritica chilensis (ZMH- P-15326).

Description. A large species, Chilean specimen [Holotype of N. dendritica chilensis ] from Puerto Aguirre 60 mm long, 6 mm wide for approximately 250 setigerous segments. Body broad, depressed in thoracic region, cylindrical in abdominal region. Thorax with 15–30 setigers, depending upon size: larger specimens with more thoracic setigers. Branchiae from setiger 7–8, continuing to posterior end.

Prostomium broadly rounded on anterior margin ( Figs. 46 A, 47A); no eyespots; no nuchal organs observed. Peristomium a single narrow folded achaetous ring ( Figs. 46 A, 47A); proboscis large, multilobed ( Fig. 46 A).

Thoracic notopodial postsetal lamellae broadly triangular ( Fig. 46 B); abdominal notopodial postsetal lamellae similar, but not as broad and elongated ( Fig. 46 C). Thoracic neuropodial postsetal lobes foliaceous ridges with uppermost edge prolonged ( Fig. 46 B); abdominal neuropodial postsetal lobes lower, less foliaceous ( Fig. 46 C).

Thoracic notosetae all crenulated capillaries; abdominal notosetae including capillaries, 2–3 furcate setae and 5–6 deeply imbedded aciculae; furcate setae with unequal tynes, longest blunt on tip, shortest thin, pointed, with about 10 thin needles between tynes ( Fig. 47 D); shaft with numerous crowded transverse rows of barbs merging with bases of needles. Thoracic neurosetae including three rows of uncini and subuluncini intermixed with capillaries ( Fig. 47 B), especially in ventral-most portion of fascicles; uncini including smooth spines ( Fig. 46 F) and less numerous smaller, weakly ribbed uncini ( Fig. 46 D); subuluncini with minute barbs on capillary extension ( Figs. 46 E, 47B). Abdominal neurosetae including capillaries and 5–6 smooth spines ( Figs. 46 G, 47C).

Abdominal parapodia dorsally elevated, forming channel with parapodia and setae of right and left sides nearly overlapping medially. Anus terminal, surrounded by lobes, cirri lacking.

Remarks. N. dendritica chilensis Hartmann-Schröder is here raised to full species status. This species is similar to N. dendritica , but differs because the neuropodial postsetal lobes are prolonged on their superior most margins instead of being reduced to a small papilla as is typical for N. dendritica . Furthermore, the thoracic neuropodial uncini are mostly smooth instead of being mostly ribbed. The three juvenile specimens from Ecuador (USNM 60637) have more uncini with transverse ridges in the thoracic neuropodia than the adults, but an adult identification was confirmed for the same sample and it is not known how the various setal types develop in orbiniids.

N. chilensis is also similar to N. laevigata Grube, 1855 originally described from the Mediterranean, but widely reported elsewhere in the Atlantic and Pacific Oceans. The branchial distribution reported for N. laevigata is highly variable and at odds with the majority of the genera and species examined as part of this study, where the branchiae of individual species have either a fixed segment on which they begin or at most only a narrow range of segments; exceptions are species where the branchiae begin in far posterior thoracic setigers. For N. laevigata, Eisig (1914) indicated most of the specimens he examined had branchiae from setigers 7–8, as in N. chilensis , but did range from setigers 4–11.

Hartman (1957) referred North Pacific records of N. laevigata to N. dendritica , but retained the records of N. laevigata of Monro (1933b) from the Galápagos Islands and Ecuador and added additional specimens from Peru. For these collections, Hartman (1957) noted a wide range from setigers 6–12 as a starting point for the branchiae suggesting that more than one species might be present. Variability in other characters was not observed and apart from notes on records from Florida (branchiae from setiger 4) little comparative information was presented by Hartman (1957). However, the branchial distribution reported for N. laevigata from the Americas at a minimum, is so variable, that it is likely that several species are involved. A review of the widely distributed records of N. laevigata is clearly needed.

Based on my own observations of N. dendritica from the eastern North Pacific ( Blake 1996) and the few specimens of N. chilensis available for study, the differences between the two species are not great and they likely represent a sibling species pair with subtle parapodial and setal differences representing a clinal variation over the distribution from Canada to Chile.

Distribution. Ecuador to Chile, intertidal to 10 m.

Figures

FIGURE 46. Naineris chilensis Hartmann-Schröder, 1965. Peru, (USNM 60641). A, anterior end, dorsal view; B, thoracic parapodium, anterior view; C, abdominal parapodium, anterior view; D, thoracic neuropodial uncinus; E, thoracic neuropodial subuluncinus; F – G, abdominal neuropodial uncini.

FIGURE 47. Naineris chilensis Hartmann-Schröder, 1965. Peru (USNM 60640). A, Anterior end, lateral view; B, thoracic neuropodial uncini and subuluncini; C, abdominal neurosetae spines and capillaries; D, furcate seta.