Dispio Hartman, 1951

Delgado-Blas, Víctor Hugo, Díaz-Díaz, Óscar & Viéitez, José M., 2018, New species of Dispio Hartman, 1951 and Streblospio Webster, 1879 (Polychaeta, Spionidae) from the coast of the Iberian Peninsula, Zootaxa 4410 (3), pp. 525-538 : 528

Dispio Hartman, 1951

Type species: Dispio uncinata Hartman, 1951 , by monotypy.— Delgado-Blas & Díaz-Díaz, 2016: 153–154.

Diagnosis. Prostomium spindle-shaped, fusiform, peanut-shaped, ovoid-shaped, rectangular-shaped, wedgeshaped, hourglass-shaped, anteriorly bluntly pointed, with narrow or blunt, short or long caruncle extending to middle (short) or posterior margin (long) of chaetiger 1; peristomium well-developed, expanded laterally, partially enveloping prostomium and extending around base of palps, forming low lateral wings (some species with lateral wings more developed than others); lateral wings not attached to prostomium, e.g. D. glabrilamellata , D. latilamella , D. anauncinata , and are separated from chaetiger 1; two pairs of eyes, arranged in a nearly straight line or trapezoid, or eyes absent. Well-developed, lobulated, eversible proboscis. Occipital tentacle absent. Palps short, extending to chaetigers 5–12; palps with single band of transverse rows of cilia on one side of ventral ciliated groove; palp sheaths large, with smooth edges and without special adornment, fused to base of palps. Anterior postchaetal notopodial lamellae serrated (sometimes slender with longer, or shorter digitiform papillae along margin; papillae found on lamellae up to chaetiger 13; lamellae of subsequent chaetigers lack papillae, or chaetiger 1 much broader (spoon-shaped, with shorter digitiform papillae along margin), or notopodial lamellae entire. Anterior neuropodial lamellae serrated (with shorter digitiform extensions along margin and extensions found on lamellae of up to chaetiger 4; lamellae of subsequent chaetigers lack extension) or neuropodial lamellae entire, rounded or triangular. Prechaetal notopodial and neuropodial lamellae well-developed anteriorly and low posteriorly. Branchiae from chaetiger 1, smooth, fused completely or partially with notopodial lamellae, distal ends free, continuing nearly to end of body. Accessory branchiae on posterior surface of notopodia from chaetigers 8– 30, initially with a single digitate lobe, increasing to 8 (as short nodules or fingerlike palmate lobes) digitate lobes on posterior chaetigers, or absent ( D. brachychaeta , D. magnus , D. oculata ). Each branchiae with a well-developed narrow band of cilia along inner edge, continuous with that of branchiae on other side of body and joined by a narrow transverse band of cilia across dorsum, which on posterior chaetigers runs along dorsal edge of a thin, elevated dorsal crest; ciliary band sometimes interrupted at base of branchiae. Each segment with a pair of dorsal C-shaped or J-shaped (arranged obliquely) double bands of cilia (= metameric dorsal ciliated organs) with a transverse band of cilia between them. Lateral organs between notopodial and neuropodial postchaetal lamellae present or absent. With capillary notochaetae only; notochaetae of chaetiger 1 and succeeding chaetigers in three groups, including a group of capillary chaetae dorsal to an anterior row of stout capillaries, and a posterior row of thinner capillary chaetae. Neurochaetae in three groups, two rows similar in morphology to notochaetae, plus a ventral fascicle of inferior chaetae replacing sabre chaetae; unidentate neuropodial hooded hooks in larvae and juveniles (rare in adults, with bidentate and unidentate hooded hooks integrated in same fascicle). Bidentate hooks in adults replacing anterior row of capillary neurochaetae from chaetigers 15–44. Some capillaries and sabre chaetae with a heavily reticulated and granular shaft, others only with granulation ( D. magnus , D. brachychaeta ). Some capillaries on anterior rows with distinct transverse barring pattern, composed of partitions and chambers in shafts, giving chaetae a cracked appearance; reticulations sometimes interspersed with dense groups of granules. Pygidium with midventral flap or flange and either one ( Dispio lenislamellata ) or two pairs of long cirri (D. anauncinata ) or absent ( D. magnus ), or pygidium reduced with small papillae on ventral surface ( D. latilamella ).