Leitoscoloplos pugettensis (Pettibone, 1957)

Figures 2 (C–E), 6 (A–B)

Scoloplos elongata Johnson 1901: 412 –413, P1. 10, Figs. 105–110.

Haploscoloplos elongata: Hartman, 1944: 257; 1948: 30; 1955:174.

Haploscoloplos elongatus: Hartman, 1957: 273 –275, pl. 26, Figs. 1 –11; 1960: 107–108; 1961: 265; 1963: 36; 1969: 19–22, Figs. 1–5.— Fauchald, 1972: 166.— Vargas et al., 1985: 336.— Maurer et al. 1988: 47.— Molina-Lara & Vargas Zamora, 1995: 198.— Dean, 1996a: 74. Not Imajima & Hartman, 1964.

Scoloplos (Scoloplos) pugettensis Pettibone, 1957: 163 .

Leitoscoloplos pugettensis: Blake, 1980:1 ‒18, Figs. 1–3; 1996:9‒10, Fig. 1.2.— Hobson & Banse, 1981:28.— Mackie, 1987:8 ‒9, Fig. 8.— Hernández-Alcantara & Solis-Weiss, 1993:1029.—de León-González & Rodriguez, 1996:172.

Scoloplos acmeceps: Vargas et al. 1985:336 .—Dean, 2009:146. Not Chamberlin, 1919.

Material examined. Gulf of Nicoya: Sta. 22, 9°48ˊ25″N, 84°52ˊ40″W, 22 m, muddy sand, 11 Jul 1980 (2), 1 Oct 1980, 1 (MZUCR); Sta. 24, 9°49ˊ25″N, 84°41ˊ20″W, 11 m, sand, 1 Oct 1980, 4 (MCZ 83994), 8 Jun 1981 (9); 4 Aug 1981, 3 (MZUCR): Sta. 28, 9°52ˊ16″N, 84°45ˊ30"W, 26 m, mud, 4 Aug 1981 (2): Sta. 29, 9°54ˊ55″N, 84°45ˊ15″W, 18 m, muddy sand, 1 Oct 1980 (1); 1 Apr 1982, 1 (MCZ 70322), 1 (MCZ 85626), 2 (MCZ 85695); Sta. 30, 9°54ˊ40″N, 84°45ˊ50″W, 18 m, muddy sand, 27 Jan 1980 (1). Punta Morales, Playa Blanca, 10°04ˊN, 84°58'W, lower intertidal, muddy sand, col: J. A. Vargas, 1986 (1); col: H.K. Dean, 20 Dec 1986 (31). Guanacaste, Bahia Culebra: Sta. 5, 10º35ˊ25.2″N, 85º39ˊ31.1″W, 2 m, 19 May 2011 (1); Sta. 9, 10º35ˊ30.0″N, 85º39ˊ43.4″W, 5 m, 19 May 2011 (11). Golfo Dulce, intertidal, 1996, (1), col: H. Buttner.

Description. Complete specimens 12.6, 15.7, and 18.5 mm long; 0.52, 0.54 and 0.45 mm. maximum thoracic width, respectively; incomplete specimens from 0.15–1.25 mm maximum thoracic width (Fig. 2 C). Prostomium short, conical; eyespots lacking; paired dorsolateral nuchal organs present. Peristomium short, one-half prostomial length, subequal to setiger one. Thorax with 12–17 setigers, flattened dorso-ventrally. Branchiae from penultimate thoracic segment, occasionally in last thoracic segment of smaller individuals.

Thoracic notopodia with triangular postsetal lobe, larger in posterior thoracic setigers; neuropodial postsetal lobe short, digitate, larger in posterior thoracic segments (Fig. 6 A). Abdominal notopodial postsetal lobes subtriangular in mid-body segments, shorter than branchiae (Fig. 2 D), becoming more lanceolate and subequal to branchiae posteriorly (Fig. 2 E); neuropodial postsetal lobes foliose, bifurcate, medial arm twice length of lateral branch, with well-developed subpodial flange (Fig. 2 D, E).

Camerated capillary setae present throughout thoracic setigers and abdominal neuropodia, with an additional flail setae (Fig. 6 B) accompanying camerated capillaries in abdominal notopodia.

Pygidium with long paired dorso-lateral anal cirri.

Remarks. Leitoscoloplos pugettensis was described by Pettibone (1957) from Puget Sound in Washington State from mud and gravelly sand. She synonymized Haploscoloplos elongatus (Johnson, 1901), also described from Puget Sound, and later reported from British Columbia, Canada, California and Pacific Panama.

The variability in thoracic length of this species may be correlated with the body size of Costa Rican specimens. Mackie (1987) reported 19–20 thoracic setigers in specimens from Washington State and 19–22 in specimens from British Columbia while Blake (1996) reported thorax lengths of 14–20 in California specimens.

Mackie (1987) examined paratypes of this species from Puget Sound and found branchiae first occurred as small papillae on setigers 13–15 in specimens with 19–22 thoracic setigers. Pettibone (1957) reported the branchiae from setigers 15–18 in specimens with 19–22 setigers. Blake’s (1996) California specimens were of a greater size range, with branchiae from setigers 14–20 with the onset of branchiae from the one or two most posterior thoracic segments. Costa Rican specimens agree with Blake’s California material in that the branchiae are almost always present from the last two thoracic segments.

L. pugettensis is similar to L. chilensis (Hartmann-Schröder, 1965) which is redescribed by Mackie (1987) as having a maximum of 15–16 thoracic setigers, thoracic branchiae, and morphologically similar abdominal notopodial and neuropodial lamellae. It differs from L. chilensis in the more triangular neuropodial postsetal lobes in the thorax and the shape of the branchiae which are medially expanded in L. chilensis . Flail setae have not been previously reported for L. pugettensis .

Distribution. Eastern Pacific Ocean from Alaska to Costa Rica, intertidal to 220 m. Found in muddy to sandy sediments from 11‒ 22 m. in the Gulf of Nicoya and 1.5‒ 5 m in Bahia Culebra.