Dispio bescanzae Delgado-Blas & Díaz-Díaz, 2016, sp. nov.
Creators: name: Delgado-Blas, Víctor Hugo
name: Díaz-Díaz, Oscar
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Annelida
Polychaeta
Spionida
Spionidae
Dispio
Dispio bescanzae

description: Dispio bescanzae sp. nov.
(Figure 5 A–Z)
Material examined. Atlantic coast of Venezuela, Güiria, 10º33′58″N, 62º44′21″W, shallow subtidal, soft bottom, 0.015 m 2 PVC corer, coll. Oscar Díaz-Díaz, March, 2006, holotype (ECOSUR 0178); same data for seven paratypes (ECOSUR 0179). Non type material: 12 specimens (MOBR I-1270) from El Peñon, Sucre state, Venezuela 10º27′02″N, 64º05′21″W, very fine sand 0.5 m of deep, 0.015 m 2 PVC corer, coll. Oscar Díaz-Díaz, March 2014; 21 specimens (CB OM-UC 105) from El Peñón, very fine sand 0.5 m deep, 0.015 m 2 PVC corer, coll. Oscar Díaz-Díaz, February 2015.
Description. Holotype incomplete, anterior fragment with 77 chaetigers, 26 mm long, 1.0 mm wide at chaetiger 15. Complete paratypes with 38–188 chaetigers (longest specimen in five fragments) plus 1–3 final segments with no chaetae; 8.0– 49 mm long, 0.7–1.3 mm wide at chaetiger 15; incomplete paratypes with an anterior fragment with 36–89 chaetigers, 6.0– 28 mm long, 0.7–1.0 mm wide at chaetiger 15. Color in alcohol yellowish white.
Prostomium hourglass-shaped, widest subterminally, bluntly pointed on anterior margin (Fig. 5 A–B), posteriorly tapered, with a long, triangular, raised, caruncle (Fig. 5 A–C) to end on posterior margin of chaetiger 1 (Fig. 5 A–C). With two pairs of subdermal, black eyes, arranged in a straight line (Fig. 5 A): one pair of small, lateral, kidney-shaped eyes and one pair of rounded, medial eyes, or arranged in a trapezoid, first pair rounded, and posterior pair reniform (Fig. 5 B) (eyes not observed in holotype). Peristomium long, collar-like, surrounding prostomium, separated from chaetiger 1, forming moderate lateral wings (Fig. 5 A–C). Proboscis not observed. Palps short (Fig. 5 B, C) extending to chaetigers 3–10 (chaetiger 5 in holotype); palps with single band of transverse rows of cilia on one side of ventral ciliated groove. Palp sheaths large, smooth, fused to base of palps (Fig. 5 B).
Notopodial postchaetal lamellae of chaetigers 1–2 shifted dorsally and deeply serrated. Lamellae of chaetiger 1 bearing 4 – 9 (7 in holotype) digitiform papillae along distal and middle margins (Fig. 5 A–B, D), basal margin rounded (Fig. 5 D). Notopodial lamellae of chaetiger 2 with 8 – 11 (8 in holotype) digitiform papillae along margin (Fig. 5 A, E); lamellae of chaetigers 3 – 6 with 6 – 10 (6 – 7 in holotype) digitiform papillae (Fig. 5 A, F) along margin; lamellae of chaetiger 7 with 1–8 (2 in holotype) digitiform papillae along margin (Fig. 5 A, G); lamellae of chaetigers 8 – 10 with up to 5 digitiform papillae, although some specimens with lamellae on chaetigers 8/11 – 37/44 (8–37 in holotype) with ruffled margin (Fig. 5 H); lamellae of chaetigers 37 – 44 and subsequent chaetigers with pointed ventral border (Fig. 5 H–J). Ventral and dorsal edges of notopodial and neuropodial lamellae overlapping or touching only on posterior chaetigers (Fig. 5 I–J, L). Notopodial prechaetal lamellae, small, subtriangular on chaetigers 1 – 2 (Fig. D–E), thereafter increasing in size, wider, continuing through anterior chaetigers and around chaetiger 43 becoming slender, long and triangular (Fig. I, J), thereafter diminishing in size through posterior chaetigers. Each segment with a pair of dorsal J-shaped double bands of cilia arranged obliquely with a transverse band of cilia between them (Fig. 5 K). Lateral organs between notopodial and neuropodial postchaetal lamellae visible but small on middle chaetigers (Fig. 5 L).
Neuropodial postchaetal lamellae of chaetigers 1–3 serrated and shifted dorsally. Neuropodial lamellae of chaetiger 1 with 1 – 5 (1–5 in holotype) digitiform papillae along margin (Fig. 5 D), lamellae of chaetigers 2 – 3 with 1 – 5 (1–4 in holotype) digitiform papillae (Fig. 5 E–F), lamellae of chaetigers 4 – 28/39 rounded and smooth (Fig. 5 G) (one specimen with 2 digitiform papillae on right lamellae from chaetiger 4), later becoming wider on chaetigers 29 – 40 (38 in holotype) forming a pointed upper border (Fig 5 H–I), gradually diminishing in size on subsequent chaetigers (Fig. 5 J). Neuropodial prechaetal lamellae small, rounded and wide (Fig. 5 D–F); larger in mid region but decreasing gradually in size on posterior chaetigers (Fig. 5 J). All neuropodial prechaetal lamellae not basally fused with neuropodial postchaetal lamellae.
Branchiae present from chaetiger 1 (Fig. 5 B, D) to end of body (Fig. 5 J); branchiae tapered, elongate, smooth; fused along length of notopodial lamellae, branchial tips free, distally pointed on all anterior chaetigers and slightly longer than notopodial lamellae (Fig. 5 D–F). Branchiae on middle and posterior chaetigers smaller than notopodial lamellae (Fig. 5 I–J). Each branchia with a band of cilia along inner edge. Accessory branchiae present from chaetigers 13 – 30 (16 in holotype), initially with a single, short digitate lobe that arises from dorsolateral side of body behind notopodial base, with number of lobes increasing to seven in posterior chaetigers (Fig. 5 M) arranged in two rows.
Notochaetae of chaetiger 1 arranged in a dorsal tuft and a ventral fascicle; dorsal tuft with about 30 to 40 very long, slender (Fig. 5 A, C), alimbated, smooth capillaries (Fig. 5 N) directed upwards (Fig. 5 A, C), longer than ventral fascicle; ventral fascicle arranged in two rows; anterior row comprised of stout, moderately reticulated, granulated, unilimbated capillaries (Fig. 5 O), and posterior row of slender, smooth, alimbated capillary chaetae (Fig. 5 P), longer than chaetae of anterior row, and less numerous than those comprising dorsal tuft. Notochaetae of chaetiger 2 and subsequent chaetigers arranged in three groups; first group with 2 or 3 uppermost wider, smooth, alimbated, capillaries, diminishing gradually in size and number to an anterior row of stout moderate reticulated, granulated, unilimbated capillaries (Fig. 5 Q), and a posterior row of slender, very slightly granulated, unilimbated capillaries (Fig. 5 R), longer than those of anterior row. Middle chaetigers with same structure of anterior chaetae except for an anterior row of reticulated, long, slightly bilimbate, very pointed capillaries (Fig. 5 S). Posterior chaetigers with dorsal tuft of slender, long, smooth, distally unilimbated capillaries (Fig. 5 T), and posterior row of slender, smooth, alimbated capillaries. Notopodial hooded hooks absent.
Neurochaetae of chaetiger 1 similar to notochaetae of chaetiger 1, arranged in two rows: an anterior row of stout, moderate, reticulated, granulated, unilimbate capillaries (Fig. 5 U), and a posterior row of shorter, slender, unilimbate, smooth capillary chaetae (Fig. 5 V), capillaries of anterior row shorter than those of posterior row; in addition, a ventral tuft of 4 – 5 shorter, slender, smooth, alimbated capillaries located in position of sabre chaetae. Chaetigers 2–9 similar to chaetiger 1 but with long, reticulated, slightly granulated, alimbated sabre chaetae; on chaetigers 10 – 15 (11 in holotype) sabre chaetae longer, stouter, heavily reticulated (Fig. 5 W), 2 – 3 per fascicle. Unidentate neuropodial hooded hooks (Fig. 5 X–Y) (one specimen with one bidentate hook on a posterior fascicle) replacing anterior row of capillary neurochaetae from chaetigers 20 – 27, up to six per neuropodium, accompanied by a row of smooth, slender, unilimbated capillary chaetae (Fig. 5 Y). Hooded hooks distally entire, slightly curved and hood extended distally to, or slightly beyond tip (Fig. 5 X–Y).
Pygidium with midventral flap and two long cirri (Fig. 5 Z).
Remarks. Dispio bescanzae sp. nov. is very similar to D. uncinata and D. panamensis sp. nov. Dispio bescanzae sp. nov and D. uncinata have branchiae of the same length and similarly shaped anterior postchaetal notopodial and neuropodial lamellae on the first three chaetigers, all serrated. However, Dispio bescanzae sp. nov. can be distinguished from the type material of D. uncinata, in that the former has a hourglass-shaped prostomium without lateral emarginations, notopodial lamellae on chaetigers 4 – 7/10 with digitiform papillae along margin, lamellae of chaetigers 8/11 – 37/44 with ruffled margin, lamellae of chaetigers 37 – 44 and subsequent chaetigers with pointed ventral border, ventral and dorsal edges of notopodial and neuropodial lamellae overlapping or touching only on posterior chaetigers, neuropodial lamellae of chaetigers 4 – 28/39 rounded and smooth, a pair of dorsal J-shaped double bands of cilia, anterior notopodial chaetae on posterior row with smooth, alimbated capillary chaetae, anterior neuropodial chaetae on anterior row with unilimbate capillaries, a posterior row of shorter, unilimbate, smooth capillary chaetae, hooded hooks slightly curved and sub-distally entire, the hoods open and extend distally or slightly beyond the tip of the hook. Dispio bescanzae sp. nov. is similar to D. panamensis sp. nov. in having deeply serrated anterior notopodial and neuropodial lamellae with papillae, a short caruncle, peristomium of the same length and lateral wings. However, D. bescanzae sp. nov. differs from D. panamensis sp. nov. in that the former has a hourglass-shaped prostomium, bluntly pointed anteriorly, a long, triangular caruncle, branchial tips distally pointed on all chaetigers, and the notopodial and neuropodial lamellae overlapping on posterior chaetigers.
In this species we observed one bidentate hooded hook on the posterior chaetiger of one adult specimen. See remarks about bidentate hooks in D. lenislamellata sp. nov. Further differences between this new species and the other species examined are provided in the key and Table 1.
Etymology. This species is named after Díaz-Díaz’s mother-in-law, who recently passed away, and is dedicated to her and all the women in the Bescanza family.
Type locality. Güiria, Venezuela.
Ecology. Specimens were collected in shallow water (1.5 m deep) in fine, medium and coarse sands.
Geographical distribution. Venezuela (Güiria and El Peñón).
description: Published as part of Delgado-Blas, Víctor Hugo & Díaz-Díaz, Oscar, 2016, Redescription of two species and five new species of Dispio Hartman, 1951 (Spionidae: Polychaeta) from the eastern Pacific Coast and Caribbean Sea, with a review of the genus, pp. 151-181 in Zootaxa 4178 (2) on pages 163-166, DOI: 10.11646/zootaxa.4178.2.1, http://zenodo.org/record/163174