Pseudopotamilla knightjonesae, Tovar-Hernández, María Ana, León-González, Jesús Ángel De & Bybee, David R., 2017

Tovar-Hernández, María Ana, León-González, Jesús Ángel De & Bybee, David R., 2017, Sabellid worms from the Patagonian Shelf and Humboldt Current System (Annelida, Sabellidae): Phyllis Knight-Jones’ and José María Orensanz’s collections, Zootaxa 4283 (1), pp. 1-64: 50-59

publication ID 10.5281/zenodo.828032

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Pseudopotamilla knightjonesae

sp. nov.

Pseudopotamilla knightjonesae  sp. nov.

( Figs 28–30View FIGURE 28View FIGURE 29View FIGURE 30, 33View FIGURE 33 C)

Material examined. Type material: ARGENTINA, Holotype ( UANL 8111View Materials), 8 paratypes ( UANL 8112View Materials). Santa Clara del Mar, 37°50’30”S, 57°29’58”W, intertidal, 18 January 1968, coll. J.M. Orensanz. Additional materialGoogleMaps  : ARGENTINA, UANL 8113, 20 topotypes  ; UANL 8114View Materials: Mar del Plata, Frentemar, 37°52’15”S, 57°30’48”W, intertidal, 23 December 1968, coll. J.M. Orensanz, dried tubes (40 tubes)GoogleMaps  ; UANL 8115View Materials: Santa Elena, 37°52’15”S, 57°30’48”W, intertidal, 27 January 1971, coll. J.M. Orensanz, 1 specimenGoogleMaps  ; UANL 8116View Materials: Cerro Avanzado , Restinga del SW, 10 January 2008. coll. J.M. Orensanz & M. Orensanz, 1 specimen  .

Description. Trunk length 12 mm (4–8 mm), width 0.5 mm (0.3–0.5 mm). Branchial crown length 1.5 mm (1– 2 mm), with six pairs of radioles. Seven thoracic segments (6–11 segments). Abdominal segments 53 in one paratype (holotype and other paratypes lack posterior abdomens). Radiolar flanges and palmate membrane both Species Number of Miđ-đorsal margins of Anterior peristomial Ventral lappets of collar Dorsal, glanđular Pygiđial eyes Habitat

compounđ eyes collar ring shielđs on 2nđ (rađiole 1: đorsal thoracic segment most)

absent. Long pinnules arranged in two alternating rows decreasing in length distally; radiolar tips short, as long as space of 2–4 pinnules ( Fig. 29View FIGURE 29 C). A large compound eye located proximally in second dorsal radioles ( Fig. 29View FIGURE 29 A, B). Branchial lobes short ( Fig. 28View FIGURE 28 A), with dorsal and ventral flanges: dorsal pair triangular ( Fig. 28View FIGURE 28 D), ventral pair rounded ( Fig. 28View FIGURE 28 D). Collar with dorsal margins triangular, short, fused to faecal groove; V-shaped dorso-lateral incisions ( Fig. 28View FIGURE 28 A, C, D; 29A, B, D). Anterior peristomial ring exposed partially dorsally and laterally ( Figs 28View FIGURE 28 C, D, 29A, B, D). Ventral collar lappets triangular, short, separated mid-ventrally by depth incision ( Fig. 28View FIGURE 28 B). Dorsal and ventral lips not examined. Two dorsal pinnular appendages present; two ventral radiolar appendages. Ventral sacs present. Ventral shield of chaetiger 1 entire, rectangular with rounded anterior margin ( Fig. 28View FIGURE 28 B). Chaetiger 1 notochaetae in two rows, broadly-hooded. Thoracic shields rectangular, divided transversely ( Fig. 28View FIGURE 28 B). Thoracic neuropodial tori separated from ventral shields by broad gap ( Fig. 28View FIGURE 28 B). Superior thoracic notochaetae elongate narrowly-hooded; inferior group paleate ( Fig. 30View FIGURE 30 D), arranged in two rows, with long and pointed mucro. Thoracic neuropodia with avicular uncini with several rows of small and similarly-sized teeth above main fang; breast well developed, handles twice the length of main fang ( Fig. 30View FIGURE 30 F, G). Companion chaetae with asymmetrical membrane and long handles, slightly longer than uncinial handles ( Fig. 30View FIGURE 30 H). Abdominal neurochaetae elongate broadly hooded ( Fig. 30View FIGURE 30 E). Notopodia with uncini with several rows of teeth above main fang on two thirds of its length, breast well developed and handle short ( Fig. 30View FIGURE 30 I). Pygidium bilobed ( Fig. 30View FIGURE 30 C), eyes absent. Tubes covered with sand grains ( Fig. 30View FIGURE 30 A), or embebed in hard sediment matrix ( Fig. 30View FIGURE 30 B).

Type locality. Argentina, Santa Clara del Mar, 37°50’30”S, 57°29’58”W, intertidal.GoogleMaps 

Etymology. The species is named after Dr. Phyllis Knight-Jones, in recognition for her vast research on sabellid polychaetes and also for her approval to send the sabellid collection from South America to the first author.

Remarks. Pseudopotamilla knightjonesae  sp. nov., is unique by boring into hard sediment matrix and by having a single, large compound eye, located proximally on second dorsal radioles. Pseudopotamilla platensis  is distinguishable from P. knightjonesae  sp. nov., by the presence of 2–3 eyes in each dorsal radioles 2 and 3 versus only one large compound eye located in dorsal radioles 2 in P. knightjonesae  sp. nov. In P. platensis  , the mid-dorsal collar margins are long and triangular (short in P. knightjonesae  sp. nov.). The ventral lappets of collar are even, forming right angles divided by a short incision in P. platensis  , against ventral lappets triangular, divided by a depth incision in P. knightjonesae  sp. nov. Finally, P. platensis  was found in soft bottoms, whereas P. knightjonesae  sp. nov. was found boring rocks in the intertidal zone ( Table 4).

Pseudopotamilla knightjonesae  sp. nov., differs from P. reniformis  from the White Sea for the following features: mid-dorsal collar margins triangular (rounded in P. reniformis  ); ventral lappets of collar triangular, divided longitudinally by a depth incision (rounded, shallow, divided longitudinally by a short incision in P. reniformis  ) and absence of pygidial eyes (present in P. reniformis  ) ( Table 4).


Universidad Autonoma de Nuevo Leon