Pycnogonum (Nulloviger) bifurcatum, Lee & Park & Park, 2023

Lee, Damin, Park, Jin-Ho & Park, Taeseo, 2023, Ophirion lenkoi Gudin 2023, sp. nov., Zoological Studies 62 (23), pp. 1-11 : 4-7

publication ID	https://doi.org/ 10.6620/ZS.2023.62-23
persistent identifier	https://treatment.plazi.org/id/03B08B03-FFF8-D510-FC49-312987B2180D
treatment provided by	Felipe
scientific name	Pycnogonum (Nulloviger) bifurcatum
status

Treatment

Class Pycnogonida Latreille, 1810 View in CoL Order Pantopoda Gerstaecker, 1863 Family Pycnogonidae Wilson 1878 Genus Pycnogonum Brünnich, 1764

Pycnogonum (Nulloviger) bifurcatum sp. nov. ( Figs. 3 View Fig , 4 View Fig ) urn:lsid:zoobank.org:act:E60798B4-DDDA-4698-8A6F-62B55331CFF2

Material examined: Holot ype, 1 ò, NIBRIV0000837749 (fcn DM 180109), East of Munseom Islet, Jeju-do, Republic of Korea (33°13'37"N 126°34'9.2"E), collected by trimix SCUBA diving at depth of 58 m, coll. D. Lee, 18 Jan. 2018.

Comparative material: Pycnogonum (Nulloviger) carinatum : Holotype, 1 ò, NMV J48800 About NMV , WV11 About NMV , Beware Reef , near Cape Conran, Victoria, Australia (37°49'21.0"S 148°47'24.0"E), collected by SCUBA diving at depth of 5–6 m, coll. Dr. Tim D O'Hara, 15 Apr. 1998; 2 ññ, NMV J48806 About NMV , WV5 About NMV , Cheviot Beach, Point Nepean, Victoria, Australia (38°18'00.0"S 144°40'12.0"E), collected by SCUBA diving at depth of 3.5–5 m, coll. Dr. Tim D O'Hara, 31 Mar. 1998. GoogleMaps

Description: Trunk tapering posteriorly, completely segmented, covered in intermittent spinules and tiny granules surrounded by spinules. Transverse ridge raised on posterior margin of segment 1–3, armed with dorsomedian tubercle; dorsomedian tubercle granular, about 1/3 times of trunk height. Cephalic segment protruding anteriorly, having rectangular shape at anterior part ( Figs. 3A, C View Fig , 4A View Fig ).

Lateral processes very short, touching each other but separated distally between 3 rd and 4 th, with raised dorsodistal granular ridge and median tubercle; median tubercle larger and more distinct from lateral process 1 to 4. Lateral process 1 about 0.6 times as long as basal width, having posteroventral distal process. Lateral process 4 armed with distinct dorsal tubercle as high as dorsomedian tubercle on trunk segment 1 ( Fig. 3A, B View Fig ).

Ocular tubercle 0.6 times of basal width, flattopped with posterodorsal papilla; four eyes pigmented. Post-ocular tubercle half times as high as basal width, 0.7 times of ocular tubercle ( Fig. 3A, B View Fig ).

Proboscis truncated-cone shaped, covered in many granules; basal width about two times as wide as distal width ( Figs. 3A, B View Fig , 4B View Fig ). Oral glands present.

Abdomen articulated at base, reaching beyond posterior margin of coxa 2, directing horizontally, tapering and distally rounded in dorsal view, bearing nodulous dorsodistal elevation with several spines. Dorsal surface tapering toward end and ventral surface flat in lateral view ( Figs. 3A, B View Fig , 4B View Fig ).

Palps, chelifores, and ovigers not present.

Leg 3 stout, covered in intermittent spinules and tiny granules ( Fig. 3D View Fig ). Coxa 1 as long as basal width, as wide as lateral processes, with granular ridge on distal margin except ventral surface. Coxa 2 as long as basal width, half times as wide as distal width of coxa 1 in dorsal view, longest segment among coxae. Coxa 3 about 0.8 times as long as basal width, bearing granular low process on ventrodistal margin. Femur half times as long as basal width, longest among leg segments, with dorsodistal granular process bearing long and short spines. Tibia 1 half times as long as basal width, bearing long spine on dorsodistal margin and short spine on ventrodistal margin, having granular dorsal surface. Tibia 2 half times as long as basal width, as long as coxa 2, bearing long spine on dorsodistal margin and four spines on ventrodistal margin, having granular dorsal surface. Tarsus short, convex ventrally, 1/4 times as long as propodus, with several spines on ventral surface. Propodus almost straight, without heel spine, having 11 sole spines and seven dorsal spines. Bifurcated spines present on ventral surface of tibia, tarsus, and propodus. Main claw curved, 0.4 times as long as propodus. Auxiliary claws tiny, about 1/5 length of main claw.

Male gonopore present ventrally on the inner surface of coxa 2 of leg 4 ( Fig. 4F View Fig ). Coxal pellicula not observed.

Coloration: Specimen preserved without color notes or photo, no traces of color. Preserved specimen transparent with light yellow ( Fig. 4C View Fig ).

Habitat: The specimen was retrieved from scrapings off underwater wall face including bryozoans and cnidarians.

Etymology: Species epithet, bifurcatum, refers to the markedly bifurcated spines on the ventral surface of tibias, tarsi, and propodi in Latin. Korean name, DU-GAL-RAE-SONG-JANG-BA-DA-GEO-MI, also alludes to the shape of the spines.

Distribution: At present only type locality ( Fig. 1 View Fig ).

Measurements (mm): Holotype, trunk length, 1.38; width, 0.94; proboscis, 0.61; abdomen, 0.36. Leg 3; coxa 1, 0.17; coxa 2, 0.23; coxa 3, 0.20; femur, 0.43; tibia 1, 0.28; tibia 2, 0.22; tarsus, 0.09; propodus, 0.36; main claw, 0.16; auxiliary claw, 0.03.

Molecular data: 329 bp of mtCOI gene and 1,776 bp of 18S rDNA gene (GenBank accession No.

OQ127517; OQ134485).