Glycera juliae, Magalhães, Wagner F. & Rizzo, Alexandra E., 2012

Magalhães, Wagner F. & Rizzo, Alexandra E., 2012, Glyceridae (Annelida: Polychaeta) from Guam, Mariana Islands with description of a new species of Glycera Savigny in Lamarck, 1818, Zootaxa 3338, pp. 60-68 : 61-65

Glycera juliae sp. nov.

Figures 1 (A–K), 2 (A–F) and 3 (A–F)

Material examined. Holotype: Pacific Ocean—Apra Harbor, Guam, Mariana Islands, station B21a, 13° 26' 57.4" N, 144° 39' 48.48" W, Dec/2010, 16 m ( USNM 1178724; complete but lacks anal cirri; proboscis partly everted, not showing jaws); Paratypes: Pacific Ocean—All from Apra Harbor, Guam, Mariana Islands; station B3b, 13° 26' 46.08" N, 144° 39' 44.34" W, Dec/2010, 14 m (2, USNM 1178725; both incompletes, one with proboscis partly everted and the other with proboscis not everted); station B6e, 13° 27' 15.9" N, 144° 39' 35.57" W, Dec/2010, 16.5 m (2 on SEM stub, USNM 1178726; both incompletes, one with proboscis partly everted not showing jaws, other with proboscis completely everted showing jaws); station B5d, 13° 27' 19.70" N, 144° 39' 25.67" W, Dec/2010, 15.5 m (1, BPBM R3561; complete but lacks anal cirri; proboscis partly everted not showing jaws); station B17b, 13° 27' 0.7" N, 144° 39' 46.16" W, Dec/2010, 15.5 m (1, BPBM R3562; complete but lacks anal cirri; proboscis partly everted not showing jaws); station B18c, 13° 26' 59.6" N, 144° 39' 38.4" W, Dec/2010, 14.9 m (1, BPBM R3563; incomplete, proboscis partly everted). Non-type material: Pacific Ocean—Apra Harbor, Guam, Mariana Islands, station B25e, 13° 26' 51.52" N, 144° 39' 55.4" W, Dec/2010, 16.4 m (1, BPBM R3564; incomplete, proboscis not everted); station B16b, 13° 27' 1.95" N, 144° 39' 52.15" W, Dec/2010, 17.4 m (2, BPBM R3565; both incompletes, proboscis partly everted in one and not everted in other); station B12e, 13° 27' 10.72" N, 144° 39' 38.7" W, Dec/2010, 2.4 m (1, BPBM R3566; complete with one anal cirrus present, proboscis not everted). Guam EPA Coastal EMAP; station 26, Piti Bomb Holes, 13° 28' 23.77" N, 144° 42' 7.04" W, 10/Jan/2005 (2, BPBM R3567; one complete with one anal cirrus and proboscis partly everted, other one incomplete with proboscis partly everted); station 45, West Agana Bay, 13° 29' 24.4" N, 144° 43' 38.50" W, 13/Dec/2004 (1, BPBM R3568; incomplete, proboscis not everted).

Description. Holotype complete 47 mm long, 1.5 mm wide on anterior segments, tapering to 0.5 mm wide on very posterior chaetigers with 161 chaetigers. Paratypes all completes (or lacking last few chaetigers including anal cirri) ranging from 11–19 mm long, 0.5–1 mm wide on anterior chaetigers and 77–115 chaetigers. Mid-body segments biannulate with same sized annuli; first annulus with shallow mid-dorsal groove/subannulation ( Fig. 3 E). Prostomium and body segments covered with dark brown speckles on dorsum and ventrum, except for inter-segmental areas ( Figs 3 E, F); parapodial lobes and cirri also darkly pigmented ( Fig. 3 E).

Conical prostomium with 9–12 rings and mid-dorsal groove throughout ( Figs 1 A, B); a pair of oval nuchal organs situated in a shallow pit of about 4–5 μm ( Figs 1 A, 2A, B). Proboscis with two types of papillae arranged in several longitudinal rows with subapical tufts of cilia: 1. numerous conical papillae with straight, median, longitudinal ridge on posterior surface ( Figs 1 D, 2C–E); 2. isolated, short and broad, oval to globular papillae without ridges ( Figs 1 E, 2C and F). Proboscis with four terminal hook-shaped jaws and ailerons with rounded triangular base ( Fig. 1 C).

First two pairs of parapodia uniramous; following parapodia biramous. Two slender, triangular to digitiform prechaetal lobes, notopodial prechaetal lobe slightly shorter than neuropodial lobe; both becoming longer and thinner posteriorly ( Figs 1 F–K, 3A). Two short postchaetal lobes, and rounded anteriorly; in following parapodia notopodial lobe becomes sub-triangular and longer than rounded neuropodial lobe; in very posterior parapodia, notopodial lobe shorter ( Figs 1 F–K). Dorsal cirri from parapodium 2, oval to globular and placed near to parapodial base ( Figs 1 F–K, 3A). Ventral cirri short and conical on anterior parapodia, digitiform and as long as postchaetal lobes on posterior parapodia; situated near parapodial base ( Figs 1 F–K, 3A). Branchiae retractile, simple digitiform, present from parapodium 22 on holotype, about as long as neuropodial prechaetal lobes and attached medially on anterior side of parapodia (only observed on mid-body segments of holotype, Figs 1 H, 3E).

Notopodia with up to 3 weakly curved capillaries with spinules covering one side of the blade ( Figs 3 B,C). Neuropodia with 3–8 compound spinigers with blades of different lengths and spinules along blades ( Figs 3 B–D).

Pygidium dark coloured with anal aperture placed dorsally and a pair of slender cirri, as long as last 3–4 segments ( Fig. 1 B).

Remarks. Glycera juliae sp. nov., seems to be closely related to Glycera macintoshi Grube, 1877 and Glycera nicobarica Grube, 1868 by the morphology of parapodial structures although it differs on the absence of ridges on the proboscidial papillae and shape of ailerons. It has been argued that the morphology of the posterior side of the proboscidial papillae may be obscured due to bad preservation (Böggemann pers. comm.) but the fixation and preservation of specimens of G. juliae sp. nov., followed standard procedures and we have examined several specimens in SEM and oil immersion light microscopy and none of the papillae showed well-defined ridges as present in G. nicobarica and G. macintoshi . Additionally, G. juliae sp. nov. differs from G. macintoshi by the presence of only one branchial ramus (up to 6 rami in G. macintoshi ) and anterior parapodia with two short postchaetal lobes (only one medially inserted in G. macintoshi ) and from G. nicobarica mostly by the presence of ailerons with rounded triangular bases in G. juliae sp. nov. and ailerons with triangular bases in G. nicobarica .

The new species resembles only superficially to Glycera sphyrabrancha Schmarda, 1861 , Glycera branchiopoda Moore, 1911 , Glycera guatemalensis Böggemann & Fiege, 2001 , Glycera semibranchiopoda Imajima, 2009 , and Glycera southeastatlantica Böggemann, 2009 by the shape and types of proboscidial papillae. However, G. sphyrabrancha and G. guatemalensis have ailerons with deeply incised bases. Glycera sphyrabrancha also has simple, digitiform branchiae, but these are not retractile as in G. juliae sp. nov.; the latter has numerous conical papillae with straight, median, longitudinal ridge, while G. sphyrabrancha does not have any ridges. Glycera branchiopoda has ailerons with pointed triangular base and parapodia with only one rounded postchaetal lobe, while G. juliae sp. nov. has ailerons with rounded triangular base and two short and conical to triangular postchaetal lobes. Branchiae are absent in G. semibranchiopoda and G. southeastlantica and present in G. j u l i a e sp. nov.; postchaetal lobes are short, initially blunt triangular and posteriorly rounded in G. southeastatlantica and in G. juliae sp. nov., notopodial postchaetal lobe is distinct from neuropodial one, being slender and elongated on mid- or posterior end parapodia.

Etymology. The species is dedicated to Dr. Julie H. Bailey–Brock for her contribution to the study of the polychaetes from the Mariana Islands and for her encouragement and guidance to the author (W.F.M.) on the study of polychaetes.

Distribution. The type locality is Apra Harbor, Guam, Mariana Island. This species has also been found further north the type locality at Agana Bay, Guam.

Figures

FIGURE 1. Glycera juliae sp. nov. A, anterior end in dorsal view with proboscis partially everted (paratype, USNM 1178725); B, posterior end segments and pygidium with one slender anal cirrus (other one lost), dorsal view; C, aileron; D, conical papilla (type 1), posterior view; E, oval to globular papilla (type 2), posterior view; F, parapodium 5, posterior view; G, parapodium 24, anterior view; H, parapodium 25, posterior view; I, parapodium 80, posterior view; J, parapodium 60, posterior view; K, parapodium 90, posterior view.

FIGURE 3. Glycera juliae sp. nov. A, parapodia 10 (superior) to 12, dorsal view; B, parapodium from mid-body chaetiger showing simple capillaries and spinigerous compound chaetae; C, detail of chaetae; D, spinigerous neurochaeta; E, mid-body segments of holotype (USNM 1178724); F, dorsal pigments from prostomium of holotype. (dc, dorsal cirrus, vc, ventral cirrus, pre, prechaetal lobes, post, postchaetal lobes, br, branchia).