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

Material examined. Type material: ARGENTINA, Holotype ( UANL 8111 View Materials ), 8 paratypes ( UANL 8112 View Materials ). Santa Clara del Mar, 37°50’30”S, 57°29’58”W, intertidal, 18 January 1968, coll. J.M. Orensanz. Additional material GoogleMaps   : ARGENTINA, UANL 8113, 20 topotypes   ; UANL 8114 View 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 8115 View Materials : Santa Elena, 37°52’15”S, 57°30’48”W, intertidal, 27 January 1971, coll. J.M. Orensanz, 1 specimen GoogleMaps   ; UANL 8116 View 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. 29 View FIGURE 29 C). A large compound eye located proximally in second dorsal radioles ( Fig. 29 View FIGURE 29 A, B). Branchial lobes short ( Fig. 28 View FIGURE 28 A), with dorsal and ventral flanges: dorsal pair triangular ( Fig. 28 View FIGURE 28 D), ventral pair rounded ( Fig. 28 View FIGURE 28 D). Collar with dorsal margins triangular, short, fused to faecal groove; V-shaped dorso-lateral incisions ( Fig. 28 View FIGURE 28 A, C, D; 29A, B, D). Anterior peristomial ring exposed partially dorsally and laterally ( Figs 28 View FIGURE 28 C, D, 29A, B, D). Ventral collar lappets triangular, short, separated mid-ventrally by depth incision ( Fig. 28 View 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. 28 View FIGURE 28 B). Chaetiger 1 notochaetae in two rows, broadly-hooded. Thoracic shields rectangular, divided transversely ( Fig. 28 View FIGURE 28 B). Thoracic neuropodial tori separated from ventral shields by broad gap ( Fig. 28 View FIGURE 28 B). Superior thoracic notochaetae elongate narrowly-hooded; inferior group paleate ( Fig. 30 View 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. 30 View FIGURE 30 F, G). Companion chaetae with asymmetrical membrane and long handles, slightly longer than uncinial handles ( Fig. 30 View FIGURE 30 H). Abdominal neurochaetae elongate broadly hooded ( Fig. 30 View 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. 30 View FIGURE 30 I). Pygidium bilobed ( Fig. 30 View FIGURE 30 C), eyes absent. Tubes covered with sand grains ( Fig. 30 View FIGURE 30 A), or embebed in hard sediment matrix ( Fig. 30 View 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