Pycnogonum rickettsi Schmitt, 1934

de Leon-Espinosa, Angel & de Leon-Gonzalez, Jesus A., 2015, Pycnogonids associated with the giant lion's-paw scallop Nodipectensubnodosus (Sowerby) in Ojo de Liebre Bay, Guerrero Negro, Baja California Sur, Mexico, ZooKeys 530, pp. 129-149 : 139-140

Taxon classification Animalia Pantopoda Pycnogonidae

Pycnogonum rickettsi Schmitt, 1934 Fig. 5

Pycnogonum rickettsi Schmitt 1934: 62, Fig. 1 A-D.

Pycnogonum rickettsi . Child and Hedgpeth 2007: 665; Hilton 1943b: 19; Hedgpeth 1975: 41a7, 424; pl. 99, fig. 3; Hedgpeth and Haderlie 1980:638, fig. 27.2.

Material examined.

Ojo de Liebre Bay, Guerrero Negro, Baja California Sur, scallop fishing area: La Concha, 27°50'35"N, 114°16'22"W, (UANL-FCB-PYCNO-0054), AC-3 (1♀), 01/12/2012.

Description.

Proboscis robust, longer than wide, slightly down-curved, articular membrane at base of proboscis narrow (Fig. 5 A–C).

Ocular tubercle high, bell-shaped, with two pairs of large strongly pigmented eyes (Fig. 5C).

Trunk robust, segmented, integument granular (Fig. 5A, C), with reticulations evident on dorsal and ventral surfaces. Fully segmented, first three trunk segments armed with a high dorsal ridge at posterior end of each body segment.

Lateral processes separated by approximately one third of their width, all as long as wide, those of the first segment are directed forward, the second and third lateral processes are directed straight out and the fourth ones point backwards (Fig. 5A).

Legs: Coxae I and II subequal, coxa III shortest, articular membrane between segments wide. Femur is the longest segment, with two conical projections on dorsodistal end and a group of isolated setae on ventral surface. Tibia I is slightly shorter than femur and is nearly twice the length of tibia II, with two dorsodorsal conical projections, similar to those found on the femur, with a strong recurved spine between the conical projections, and isolated setae on the ventral surface; tibia II short, with a slight dorsal depression mid-segment, a strong distal recurved spine, and a small group of ventral setae placed in 3-4 regular rows. Tarsus short, with 6-7 rows of setae that almost completely cover the ventral surface. Propodus nearly as long as femur, with four rows of sole spines. Claw approximately 50% of propodus length, auxiliary claws absent (Fig. 5E).

Chelifores: absent

Palps: absent

Oviger: absent.

Female gonopore evident, oval, well-defined, situated on dorso-lateral surface of coxa II of fourth pair of legs (Fig. 5D).

Abdomen 0.8 mm long, smooth, cylindrical, reaching distal margin of coxa I on fourth pair of legs, with four small spines on middle dorsal area (Fig. 5C), posterior end truncate (Fig. 5A, D), and anus terminal.

Standard measurements.

Proboscis 2.2 mm long, 0.9 mm wide.

Body 2.08 mm long from anterior end of cephalic segment to end of fourth lateral processes, 1.91 mm wide between second pair of lateral processes.

Leg 1 6.0 mm long from coxa I to the tip of main claw. Coxa I, 0.5 mm, coxa II, 0.6 mm, coxa III, 0.3 mm, femur 1.2 mm, tibia I, 1.1 mm, tibia II, 0.6 mm, tarsus, 0.2 mm, propodus 1.0 mm, claw 0.5 mm.

Distribution.

Puget Sound to the southern California Bight; this is the first record from western Mexico.

Remarks.

Only a single female specimen was collected in this study. The specimen reported in this paper differs in some characteristics from the holotype of Pycnogonum rickettsi . However, we think it may be premature to describe this specimen as a new species because our specimen is a female and that described by Schmitt (1934) is a male.