Eurycyde bamberi, de Leon-Espinosa, Angel & de Leon-Gonzalez, Jesus A., 2015

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 : 130

Taxon classification Animalia Pantopoda Ammotheidae

Eurycyde bamberi sp. n. Fig. 1

Material examined.

Holotype (1 male), Ojo de Liebre bay, Guerrero Negro, Baja California Sur, scallop fishing area: El Datil, 27°48'43"N, 114°15'06"W, (UANL-FCB-PYCNO-0031), AD-1, (1), 01/12/2012.

Description.

Proboscis articulated, proximal portion a cylindrical tube approximately one quarter of the total size, distal part pyriform, 3 smooth lips (Fig. 1 A–B).

Chelifores with three segments, first scape segment slightly longer than second, with a long spine at the distal part directed forward, second scape segment with five ventrolateral spines and a smaller dorsal spine. Third segment approximately 1/3 the size of the second one, spineless, widening towards the distal part, ending in a smooth chela without auxiliary teeth (Fig. 1C).

Palp consists of ten segments, first one short, 0.05 mm long, second segment shorter than first one (1/3 its length), third segment approximately 0.55 mm long with two dorsal spines between the second and final third of the segment; the fourth segment smaller, 1/3 of the third one, with a spine on the distal end; fifth segment as long as the third one, with a line of lateral spines aligned forward starting in the second third of the segment and ending at the distal end; sixth segment small, half the size of the fourth, with three spines on the ventrodistal end, two on the ventral side and one at the dorsodistal end; seventh to ninth segments similar in both size and shape, with two rows of spines running along the entire ventral surface; tenth segment smaller than previous ones, with a row of spines on the ventral surface (Fig. 1D).

Small ocular tubercle, inserted at edge of cephalic segment, without lateral spines, twice as tall as its diameter capped with an inverted cone, with four pronounced eyes (Fig. 1B).

Trunk compact, spineless, suture lines slightly marked (Fig. 1 A–B).

Lateral processes smooth, well-developed, longer than the width of the body and without spines or tubercles, separated by less than half of their own diameter.

With four long, slender walking leg pairs. Coxa I very short (0.1mm) with two thick dorsolateral tubercles, coxa II longer (0.17mm) with two short spines, one median dorsal and one ventrodistal, coxa III (0.14mm) slightly shorter than coxa II, with two short ventral spines, one median and one at the dorsodistal end. Femur smooth, armed with three long distal spines, one dorsal and two lateral. Tibiae I and II long, nearly subequal. Tibia I, armed with three dorsal and two mid-lateral spines, a long dorsodistal spine, seven ventral spines, smaller, in a row and two longer distal spines. Tibia II, with six long dorsal spines and a ventral row with 22 smaller setae. Tarsus, with a ventral row formed by eight setae. Propodus slightly curved, armed with seven dorsal spines and a ventral row of 19 sole spines. Thick claw, without auxiliary claws (Fig. 1F).

Oviger composed of 10 segments, first three short, segments 1 and 3 subequal, segment 2 slightly longer, fourth and fifth segments long and subequal, first to fourth segments without spines or setae, fifth segment with a ventral row of five moderately sized setae, sixth segment 2/3 the length of segment 5, with three ventral and two apical setae located dorsally, seventh to tenth segments smaller, with two rows of spines, the first row with the formula 7: 5: 5: 8, and the second row of spines similar in shape, but smaller than the first ones with the formula 9: 7: 6: 8. Last segment ends in a thick terminal claw (Fig. 1E). Eggs not observed.

Long cylindrical abdomen, extended at an angle of 45°, exceeding the length of the lateral processes and first coxae combined, of the fourth pair of legs; distal end of abdomen with 7 long thin spines, the rest smooth (Fig. 1B).

Standard measurements.

Proboscis 1.3 mm long, divided in two segments, proximal one of 0.35 mm long, distal segment 0.95 mm long, 0.35 mm wide.

Body 1.5 mm long from anterior end of cephalic segment to end of fourth lateral processes, 1 mm wide between second pair of lateral processes.

Leg 1 3.72 mm long from coxa I to the tip of main claw. Coxa I, 0.1 mm, coxa II, 0.17 mm, coxa III, 0.14 mm, femur 0.81 mm, tibia I, 0.89 mm, tibia II, 0.97 mm, tarsus, 0.08 mm, propodus 0.44 mm, claw 0.12 mm.

Oviger 2.45 mm long, first segment 0.09 mm, second 0.11 mm, third 0.09 mm, fourth 0.62 mm, fifth 0.56 mm, sixth 0.40 mm, seventh 0.2 mm, eighth 0.13 mm, ninth 0.12 mm, tenth 0.13 mm.

Distribution.

This species is known only from Ojo de Liebre bay, Guerrero Negro, Baja California Sur, Mexico.

Etymology.

Specific name is in honor of Roger Bamber for his great work on the knowledge of pycnogonids, who died recently on February 16, 2015.

Remarks.

Eurycyde is a relatively small genus. Until the present report, it was represented by 19 species and of these, only Eurycyde spinosa Hilton, 1916 and Eurycyde clitellaria Stock, 1955 have been previously recorded for the eastern Pacific. The first one was described from Laguna Beach, California, the second described from the Virgin Islands in the Caribbean Sea and later reported from Tenacatita Bay, Jalisco by Child (1979). This report is the third finding of a species of Eurycyde in the eastern Pacific. Table 1 shows important characteristic features of these Eurycyde species.

Based on the key proposed by Nakamura and Chullasorn (2000), this species is very close to Eurycyde hispida Kroyer, 1844, described from Greenland and whose type material has been lost; Eurycyde hispida has also occasionally been reported from the coasts of the north Atlantic. Eurycyde hispida has plumose spines on its legs and abdomen, lateral process with setae laterally, coxa I without a lateral tubercle, and a tall thin ocular tubercle. In contrast, the new species has simple spines on the abdomen and legs, lateral processes without tubercles or spines, coxa I with two dorsolateral spines, and the ocular tubercle short, narrowing towards the tip. Another closely related species is Eurycyde spinosa Hilton, 1916. These two species can be separated by the presence of a large posterior spine on each coxa I, and the ocular tubercle is conical with one large spine and several smaller spines in Eurycyde spinosa , while Eurycyde bamberi sp. n. does not have posterior spines on the first coxa, and the ocular tubercle is globose, distally pointed, without spines.

The following species are illustrated and described in full since their previous descriptions are quite outdated and in some cases, like Nymphopsis duodorsospinosa , very incomplete. This will help facilitate future identification of eastern Pacific pycnogonids as well as help to differentiate new species as they are collected and described from this region.