Laubieriopsis cf. cabiochi ( Amoureux, 1982 )

Magalhães, Wagner F., Bailey-Brock, Julie H. & Rizzo, Alexandra E., 2014, Laubieriopsis petersenae n. sp. and L. cf. cabiochi (Amoureux, 1982) (Polychaeta: Fauveliopsidae) from dredge disposal sites off Honolulu, Hawaii, Zootaxa 3893 (1), pp. 143-150 : 148

Laubieriopsis cf. cabiochi ( Amoureux, 1982)

Figure 3

Fauveliopsis cabiochi Amoureux, 1982: 192 –194, fig. 3.

Fauveliopsis cabiochi ; Blake & Petersen, 2000: 34.

Laubieriopsis cabiochi ; Petersen, 2000: 503–512, fig. 2A–K, N–P, Tables 2–3.

Material examined. Pacific Ocean—Mamala Bay, south shore of Oahu, Hawaii: station 6.1.B, 21°13'19.68"N, 157°57'5.7"W, Jun/1995, sandy mud, 498 m (3, BPBM R3649); station 7.1.B, 21°14'0.66"N, 158°00'1.49"W, Jun/ 1995, muddy sand, 416 m (3 on SEM stub, USNM 1251833; 4, BPBM R3650); station 8.2.B, 21°14'30.42"N, 158°01'31.02"W, Jun/1995, muddy sand, 333 m (4, BPBM R3651); station 16.1.B, 21°14'54.12"N, 157°59'31.98"W, Jun/1995, sandy mud, 397 m (1).

Description. Body 2.2–5.0 mm long, 0.2–0.3 mm wide, 21 chaetigers ( Fig. 3 A), one specimen with 20 chaetigers (BPBM R3651). Body slender, rounded dorsally, flattened ventrally, not widening posteriorly. Segments distinct, shorter in thorax; abdominal segments twice longer than thoracic ones. Segments 4 and 5 biannulated, with prechaetal short annulus. Epithelium smooth, iridescent, with micropapillae present throughout but difficult to detect under light microscope.

Prostomium retractile and partially everted in some specimens ( Fig. 3 B), small, rounded with a pair of lateral nuchal organs as large fields of long cilia dorsally. Peristomium as a complete ring, longer than thoracic chaetigers ( Fig. 3 B).

Parapodia biramous throughout, best developed in chaetigers 1–4; parapodial lobes inconspicuous throughout. Interramal papillae short-stalked, closer to neuropodia. Two epidermal glands per segment, dorsal to notopodia, short-stalked, smooth, rounded and present throughout.

Chaetigers 1–4 bear two slender unidentate and two thick bidentate aciculae per ramus ( Fig. 3 D, E). Some specimens present transitional chaetiger 4 with companion capillaries instead of thick bidentate chaetae. All chaetae with median rows of spines, being smooth only basally and distally ( Fig. 3 E). Chaetigers 5–21 have one unidentate acicula and one outer companion capillary per ramus (cA/Ac sensu Petersen 2000).

Unpaired genital papilla present at the right side of chaetigers 8–9.

Pygidium retracted in all specimens; anus terminal; chaetae not extending beyond pygidium ( Fig. 3 C).

Remarks. The Hawaiian material agrees with the material from the northern Atlantic Ocean described in Petersen (2000). The only distinctive feature is the presence of prominent parapodial lobes in the type material described in Petersen (2000) and not projected in the Hawaiian material.

Reproduction. No specimens were found with reproductive features.

Distribution. This species was previously known from the northern and southern Atlantic Ocean; continental slope south of Ireland, Faroe Islands, and Iceland (Petersen 2000) and Campos Basin, Brazil (Rizzo, pers. obs.) and it is herein described for the first time in the Pacific Ocean as L. cf. cabiochi . This disjunct distribution is unlikely but the specimens collected in Hawaii are morphologically very similar to those described in Petersen (2000). The only morphological feature observed to be distinct was the presence of distinct parapodial lobes in the anterior four segments of the type material and indistinct throughout in the Hawaiian material. Although it could represent a different species, molecular data would be necessary to confirm if this is a complex of morphologically similar species.

Figures

FIGURE 3. Laubieriopsis cf. cabiochi (USNM 1251833). A, complete specimen (ch, chaetiger); B, anterior end showing prostomium (pr) and peristomium (per), latero-ventral view; C, posterior end showing pygidium (pyg); D, acicular chaetae of anterior end; E, detail of aciculars showing rings of denticles.