Pareurythoe borealis (Sars)

Pareurythoe borealis (Sars) View in CoL

Eurythoe borealis Sars, 1862: 58–59 View in CoL ; McIntosh 1900: 224–226, pl. 27, fig. 16 (ant. end); George and Schröder 1985: 52–53, fig. 7.

Amphinome vagans View in CoL ?: M’Intosh 1869: 406, pl. 15, fig. 1 (chaetae).

Pareurythoe borealis View in CoL : Pettibone 1963: 60–61, fig. 13c; Hartmann-Schröder 1996: 28; Jirkov 2001: 239,

Type material

Norway. Holotype lost.

Additional material

Mediterranean Sea. One specimen ( USNM 58944), between Riou and Gran Conglu, 55 m, 9 April H. Zibrowius, coll. (complete ( 4 mm long, fusiform), slightly bent ventrally; anterior eyes round, 5–6

large as posterior ones; caruncle sinuous, reaching almost posterior margin of chaetiger 3; branchiae chaetiger 2 with 4–5 filaments, median and posterior chaetigers with 4 filaments; anus terminal, anal entire, rounded, not notched).

Northweastern Atlantic. Thirty specimens ( USNM 27347 About USNM ), off Cheseapeake Bay , Virginia, United States Commission Albatross, Sta . 2421 ( 37.11 N, 74.57W), 115 m, 3 June 1885 (very small ( 2–5 mm long parallel), bent ventrally; anterior eyes reniform, rarely oval, 4–5 times as large as posterior ones; sinuous, almost reaching posterior margin of chaetiger 2; branchiae from chaetiger 2; larger specimens

2 filaments, up to 3 in median segments, decreasing to 1 in posterior segments (smaller specimens

1 filaments per region); anus subterminal, anal cirri fused in anal plate, medially notched.

Diagnosis

Pareurythoe with caruncle extended along chaetigers 1–3, reaching posterior part of chaetiger 3; depression deep. Anterior eyes reniform, 6–8 times larger than posterior round eyes. Branchiae chaetiger 2 with 1–2 filaments. Median segments with spurred neurochaetae, largest tine denticulate

Description

Abridged after McIntosh (1900, 225–226). Body 25–38 mm long, 41–67 segments. Eyes red, anterior twice as large as posterior ones. Caruncle reaches anterior border of chaetiger 3. Branchiae from with 4 filaments, continue almost to the last segment. Parapodia with two types of notochaetae,

with longer tine serrated and harpoon chaetae; neurochaetae include coarser furcates with less

Anal plate with margin crenulate.

Remarks

Pareurythoe borealis (Sars) was described with a specimen collected of Manger, Norway, in sediments 109–126 m water depth, but it was lost ( Sars 1862, 58; Oug et al. 2014, 224), such that besides diagnosis, no topotype specimens have been illustrated or redescribed, and a neotype needed to delineate the species and evaluate whether it may be present in Northern European and Atlantic coasts. The anterior end was illustrated by Pettibone (1963, 58, fig. 13

one specimen collected off Chesapeake Bay, in sediments at 115–126 m water depth, and her was reproduced by Jirkov (2001, 239, fig. 1). Pettibone (1963, 60) indicated that the caruncle along the first three chaetigers, and that branchiae start in chaetiger 2 with a few filaments (3–

her figure confirms this.

The record by Fauvel (1923, 129) follows Racovitza (1896), but the anterior end does not Pareurythoe species but rather resembles a typical Eurythoe because the caruncle is cushion-shaped a median and two lateral lobes. McIntosh (1900), in contrast, included an illustration of the anterior end shows a thin, sigmoid caruncle, typical of Pareurythoe .

JOURNAL OF NATURAL HISTORY

Distribution

Originally described from Norway, it has also been recorded from the northeastern United States transatlantic distribution needs confirmation once the neotype and additional specimens are studied