Hedgpethia nosferatu, Sabroux, 2025

Sabroux, Romain, 2025, The genus Hedgpethia Turpaeva, 1973 (Pycnogonida: Colossendeidae): a review and a new species, European Journal of Taxonomy 1026, pp. 147-170 : 158-161

Hedgpethia nosferatu sp. nov.

urn:lsid:zoobank.org:act:

Figs 1–2, Table 1

Hedgpethia sp. – Sabroux et al. 2023a [phylogeny]: figs 2–3, tab. 1.

Etymology

In apposition. Named after Nosferatu, a popular vampire character appearing for the first time in ‘Nosferatu, eine Symphonie’ (1922), in reference to the somewhat bat-wing-like outline of the femorae.

Type material

Holotype

SOUTHWEST PACIFIC • ♀; south of New Caledonia, south-southeast of Isle of Pines ; 22°56′37.7952″ S, 167°39′23.9832″ E; depth 310–403 m; 23 Aug. 2016; KANACONO stn DW4745; GenBank nos: OP985938 (mitochondrial genome), OQ065619 (18S); MNHN-IU-2016-6868 .

Description ( holotype, ♀ (MNHN-IU-2016-6868))

MEASUREMENTS (mm). Trunk + cephalon length 2.2; trunk width at second trunk segment (lateral processes included) 1.1; proboscis length 3.8; abdomen length 0.09; femur length 4.7; tibia 1 length 7.5; tibia 2 length 4.1; tarsus length 0.9; propodus length 0.8; main claw length 0.4.

Trunk fully segmented, compact. Trunk segments 1–3 posterior margin flaring and carrying one small dorsomedian pointed tubercle. Ocular tubercle medium-sized, pointed at tip, about 1.6 × as tall as base width, carrying four pigmented eyes. Lateral sense organs inconspicuous or absent. Palp insertion on cephalon at end of short anterolateral projection aside proboscis, base of which seemingly segmented. Oviger insertion ventral, just before first trunk segment lateral processes, individualised as short ventral projection. Lateral processes shorter than wide, without ornamentation, separated by less than own diameter.

Proboscis about 1.7 × as long as whole body. Base constricted, not as basal stalk. Proboscis inflating from base to mid-length with gentle constriction about proximalmost third. Distalmost half tapering, distalmost third almost pipette-like. Tip rounded.

Abdomen ventralised, not visible dorsally, directed diagonally downward, not reaching beyond lateral processes. Anus at tip.

Chelifore absent.

Palp 9-articled. Article 1 shortest, shorter than wide. Article 2 longest, curved. Article 3 about twice as long as wide. Article 4 long, slightly more than half as long as article 2. Article 5 short, about twice as long as wide, more than 5 × as short as article 4. Article 6 thrice as long as wide, 1.7 × as long as article 5. Article 7 about as long as article 6. Articles 8 and 9 about 0.9 × as long as article 6. Articles 2 to 4 sparsely setose, articles 5 to 9 very setose ventrally. Individualised medium size setae carried on dorsodistal margin of articles 2 and 3.

Oviger 10-articled plus terminal claw. Articles 1 and 3 about as long as wide. Article 2 slightly longer. Articles 4 and 6 longest, subequal. Article 5 short, about 5 × as small as article 4. Articles 7–10 forming strigilis, article 7 longest, articles 8 and 9 subequal, article 10 shortest. Strigilis spines spatulate, denticulated distally, distributed in fields. Distalmost ventral spine of article 10 curved, forming subchela with terminal claw. Terminal claw wedge-like, with ventral cutting edge.

Legs coxae 1–3 about as short as wide. Coxa 1 dorsally ornamented with dorsal spinules. Femur widest, with seven more or less elevated mediodorsal conical tubercles carrying one seta each, three of which on proximal half about half as high as femur width. Tibia 1 longest, 1.6 × as long as femur, carrying dorsally short setae, one slightly longer on distal margin. Tibia 2 slightly longer than half tibia 1, 0.9 × as long as femur, with one long seta dorsodistally and one strong spine ventrodistally. Tarsus about 0.2 × as long as tibia 2, with numerous ventral spines and more scarcely distributed dorsal spines. Propodus slightly shorter than tarsus, propodal sole carrying numerous spines. Main claw about half as long as propodus. Auxiliary claws absent.

Remarks

The femorae of H. nosferatu sp. nov. readily distinguish it from all other species in the genus. Tibia 1 is also particularly long for the genus, about 1.6 × as long as the femur. Most species have this ratio to 1.2 (e.g., H. bicornis , H. brevitarsis , H. chitinosa , H. shalei ) or below. Hedgpethia eleommata has this ratio to 1.3, H. articulata 1.4, H. magnirostris 1.5, and H. tibialis 1.6 too. Hedgpethia nosferatu differs from H. magnirostris by its taller ocular tubercle; from H. articulata by the wider propodus and tarsus; from H. eleommata by the propodus / tarsus length ratio, and the shape of the proboscis; from H. tibialis , which is geographically close ( New Caledonia), by the tarsus / propodus ratio.

Hedgpethia nosferatu is morphologically closest to H. chitinosa . Besides the above-mentioned characters, H. nosferatu differs from this species by the shape of the proboscis, and the presence of spines on the sole of the propodus. The main claw also tends to be longer relative to the propodus in H. chitinosa , although this character seems to present important variations ( Nakamura, 1987).

Sea spider diversity in New Caledonia included so far 66 nominal species listed by Bamber (2007b). Among them, 36 appear so far as endemic ( Bamber 2007b). Hedgpethia nosferatu is therefore the 67 th pycnogonid species recorded from New Caledonia, and potentially the 37 th endemic species. This is also the second species of Hedgpethia recorded from New Caledonia, after H. tibialis that was recorded north and south of the island ( Stock 1991a). The new species holotype is likely a female given the wide opening of the gonopores ventrally on coxae 2.

Geographic and bathymetric distribution

There are two main geographic components in the distribution of Hedgpethia as recorded in the literature ( Fig. 2):

A Northern Pacific distribution ( Fig. 2B) represented by seven species ( H. bicornis , H. brevitarsis , H. californica , H. chitinosa , H. elongata , H. nasica , H. spinosa ) distributed in an arch from Okinawa to California. Four of these species ( H. brevitarsis , H. californica , H. elongata , H. spinosa ) were found between 0 and 1000 m ( Table 1 ). The distribution of H. bicornis extends slightly deeper, down to 1100 m in the Okhotsk Sea ( type locality; Dudnik 2025); it was found as shallow as 303 m in the Kuril Islands, and possibly as shallow as 64 m along the southeastern coast of Kamchatka ( Losina-Losinsky 1961). Hedgpethia chitinosa was also mostly sampled within the 0–1000 m range, but two sampling events for this species are recorded to 3939 m (Bering Sea; Hilton 1943) and ca 6500 m (south off Commander Islands; Dudnik 2025). Hedgpethia nasica was found only once, at ca 4100 m deep off the California coast.

A Southern Indopacific distribution ( Fig. 2A, C) represented by eight species ( H. calva , H. dampieri , H. eleommata , H. filamentus , H. magnirostris , H. nosferatu , H. shalei , H. tibialis ) distributed from the eastern coast of South Africa to off New Caledonia and New Zealand, six of these species ( H. calva , H. dampieri , H. filamentus , H. magnirostris , H. nosferatu , H. tibialis ) were sampled uniquely above 1000 m deep. Two species have their bathymetry extending even deeper: H. eleommata was sampled around 1400–1450 m southeast off New Zealand; H. shalei was sampled on the Southwest Indian Ridge at 687 and 1414 m deep. Hedgpethia filamentus and H. shalei are the two species in this genus presently known from seamounts (Atlantis Bank and Middle of What Seamount; Staples 2019).

Hedgpethia articulata and H. dofleini spread between these two geographic groups: H. articulata has the widest know bathymetric distribution and was sampled in Indonesia (ca 2000 m deep), the Bering Sea (ca 4000 m deep) and the Gulf of Alaska ( 3620 m deep); H. dofleini was mostly sampled off both sides of Japan (from Hokkaido to Kyushu; ca 40–900 m deep) and in the Aleutian Islands (ca 80-650 m deep), but one specimen recorded on GBIF (2025) was sampled off Mayotte in the Comoro Islands ( 450 m deep).

Outside these distributions, H. caudata is the only species known off the Pacific coast of South America ( Peru; approximatively 3000 m deep), and H. atlantica is the sole species recorded in the Northeast Atlantic from around 200 m (Josephine Bank; Stock 1970) to below 1000 m deep (Galicia Bank; Stock 1991b); in the Gibraltar Strait ( 135 m deep; Stock 1987), and in the Western Mediterranean (French Mediterranean coast at a depth of 100 m; Arnaud 1987).