Armandia cf. paraintermedia Parapar & Moreira, 2015

Magalhães, Wagner F., Rizzo, Alexandra E. & Bailey-Brock, Julie H., 2019, Opheliidae (Annelida: Polychaeta) from the western Pacific islands, including five new species, Zootaxa 4555 (2), pp. 209-235 : 218

Armandia cf. paraintermedia Parapar & Moreira, 2015

Figure 7 (A–D)

Armandia paraintermedia Parapar & Moreira, 2015: 590 –595, figs 10–12.

Material examined. Tutuila, American Samoa: Sta. 11, Pala Lagoon, 14°19'20.6" S, 170°42'44.9" W, intertidal, Sept/20/2014, coll. W. Magalhães and K. Thurston (2 spms, BPBM-R3885); Sta. 12, Pala Lagoon across correction facility, 14°19'6.5" S, 170°42'57.9" W, intertidal, muddy bottom, Sept/20/2014, coll. W. Magalhães and K. Thurston (1 spm, BPBM-R3886 ) .

Diagnosis. Parapodia biramous, with parapodial prechaetal lobe, ventral lobe and minute dorsal cirrus. Anal tube funnel shaped, slightly longer than wide with 12–13 transversal striations; up to five pairs of marginal papillae of similar length, digitiform; an internal, unpaired ventral anal cirrus, short, crenulated; a pair of digitate basal papillae.

Description. Specimens 3–9 mm long, 0.2–0.3 mm wide for 27–28 chaetigers. Body slender, slightly tapering towards anterior and posterior ends. Prostomium conical, excluding palpode, longer than wide; palpode as long as 1/ 3 prostomial length, clavate, distal end with dorsal depression, spoon-shaped ( Fig. 7A, B , detail). A pair of black eyes deeply and ventrally embedded in prostomium and a third, 1.5x larger than paired ones, on dorsal side, also embedded in prostomium ( Fig. 7B ). A pair of nuchal organs present; pharynx eversible, globose and entirely covered with short cilia; oral tentacles absent ( Fig. 7B ). Branchiae present from chaetiger 2 (always absent in last three chaetigers); from anterior to mid-body, branchiae long and not meeting dorsally ( Fig. 7A ); from mid- to posterior end, branchiae decrease in length; branchiae without pigmentation.

Parapodia biramous, with parapodial prechaetal lobe, minute dorsal cirrus and ventral lobe; chaetiger 1 with quadrangular parapodial prechaetal lobe and short ventral lobe; from chaetiger 2 to posterior end, prechaetal lobe become more rounded and ventral lobe digitate and more distinct from parapodial bundle. Dorsal cirrus minute, digitate and difficult to observe. Simple capillary chaetae in two bundles; notochaetae about three times longer than neurochaetae; notochaetae 3–5 anteriorly reducing to 2–3 posteriorly; notochaetae slightly longer than branchiae when branchiae is best developed and longer than branchiae posteriorly. Neurochaetae 3–5 capillaries anteriorly reducing to 3–4 or less posteriorly. Lateral eyespots anterior to parapodia 7 on 11 chaetigers (chaetigers 7–17), black and large, usually bean-shaped; eyespots of chaetiger 7, 16, and 17 of about a third the size of others, rounded.

Anal tube funnel shaped, slightly longer than wide, as long as last 2–3 chaetigers and with 12–13 transversal striations; anal tubes preserved tapering or rectangle-shaped ( Fig. 7C, D ). Posterior border provided with up to five pairs of marginal papillae of similar length, digitiform, shorter than length of anal tube; an internal, unpaired ventral anal cirrus, short, crenulated, seen through tube wall and inserted half way anal tube; a pair of basal papillae longer than marginal ones and digitate.

Remarks. The three specimens from American Samoa agree partially with the description of A. paraintermedia Parapar & Moreira, 2015 by the shape of the anal tube and presence of minute parapodial dorsal cirrus. Differences were noted such as the size of the dorsal eyes in comparison to the right and left eyes (smaller in type material of A. paraintermedia and larger in the American Samoa specimens), size of the first pair of lateral eyes (smaller than subsequent ones in American Samoa specimens and same size as subsequent ones in type material of A. paraintermedia ) and lack of a distinct incision on the prechaetal lobes seen in A. paraintermedia .

Distribution. This species is known from Lizard Island, Australia and newly recorded to intertidal muddy bottoms in American Samoa.

Figures

FIGURE 7. Armandia cf. paraintermedia from American Samoa: A, anterior end in lateral view; B, anterior end showing detail of prostomial palpode and everted pharynx; C and D, pygidium of two individuals in lateral view. Armandia amakusaensis from Guam, Mariana Islands: E and F, pygidium of two individuals in lateral and ventral views, respectively.