Paraprionospio ( Caullery, 1914 )

Delgado-Blas, Víctor H. & Carrera-Parra, Luis F., 2018, New Phylogenetic Analysis of Paraprionospio Caullery (Polychaeta: Spionidae), with Description of a New Species from the Gulf of Mexico, Zoological Studies 57 (52), pp. 1-20 : 7

Genus Paraprionospio ( Caullery, 1914) ,

emended

Type species: Prionospio pinnata Ehlers, 1901 , designated by Caullery 1914: 358.

Diagnosis: Prostomium fusiform with rounded, truncate to slightly rounded or bluntly pointed anterior end, occasionally with slight medial peaks; with a raised, narrow ridge on the posterior region of the prostomium; caruncle absent. Eyes present or absent. Peristomium fused with first achaetous segment, forming large lateral membranous wings enclosing prostomium. A pair of grooved palpi with membranous basal sheath. Eversible bilobate proboscis. Muscular gizzard present. Chaetiger 1 well developed, distinct from preceding segments. Two or three pairs of branchiae. When three pairs of branchiae are present, these are on chaetigers 1-3, all with densely packed lamellar plates attached serially on inner to posterior face of shaft, excepting in the basal region and distal tips. When two pairs of branchiae are present, these are located on chaetigers 1-2; first pair of branchiae pinnate with few plate-like pinnules or lamellae, the second one cirriform. Each branchia entirely free from notopodial lamella. Two threadlike filaments at the base of third notopodium present in some species. Distinct transverse ridge between branchial bases of chaetiger 1 or chaetigers 1-3 as in P. africana . Dorsal ridges in middle segment present. Interparapodial pouches present or absent. Notopodial and neuropodial capillaries limbate and granulated in anterior chaetigers, replaced by alimbate, slender capillaries without granulation in middle and posterior chaetigers. Sabre chaetae starting from chaetiger 9. Neuropodial multidentate hooded hooks from chaetiger 9. Notopodial hooded hooks appearing from middle body region. Notopodial and neuropodial hooks with conspicuous striated secondary internal hooded, absent in some species. Shallow ventral furrow presents longitudinally from middle to the end of the body. Dorsal crest present or absent. Pygidium with one long and thin mid-dorsal cirrus, and two shorter ventrolateral cirri present in some species.