Liljeborgia caliginis, d & d & Acoz & Vader, 2009

d, Cédric, d, Udekem, Acoz & Vader, Wim, 2009, On Liljeborgia fissicornis (M. Sars, 1858) and three related new species from Scandinavia, with a hypothesis on the origin of the group fissicornis, Journal of Natural History 43 (33 - 34), pp. 2087-2139 : 2089-2098

publication ID	https://doi.org/ 10.1080/00222930903094647
persistent identifier	https://treatment.plazi.org/id/3A1B87EB-1C60-FFF8-FD9A-553BFBB658A2
treatment provided by	Felipe
scientific name	Liljeborgia caliginis
status	sp. nov.

Treatment

Liljeborgia caliginis View in CoL sp. nov.

( Figures 1–6 View Figure 1 View Figure 2 View Figure 3 View Figure 4 View Figure 5 View Figure 6 ) Lilljeborgia fissicornis ; Schellenberg, 1925, p. 203; Stephensen, 1931, p. 222–225 (in part); Stephensen, 1938, p. 196–197 (in part).

Material examined

Svalbard, Rossøya , R / V Jan Mayen, sta. 1188–96, 81°27′ N, 020°00′ E, 1010 m, 13 September 1996: three paratypes, leg. Jan Roger Jensen, TSZCr 13867 GoogleMaps ; Svalbard, R / V Jan Mayen, sta. 807–97, 80°49′ N, 013°53′ E, 1180 m, RP sledge, 8 September 1997, about 12 adults (female holotype + 11 paratypes) and 5 juveniles, TSZCr 10408 GoogleMaps ; Svalbard, Questrenna , R / V Jan Mayen, sta. 809–97, 80°47.9′ N, 013°51.6′ E, 1061 m, RP sledge, 08 September 1997: three paratypes, TSZCr 10276 GoogleMaps ; Svalbard, Questrenna , R / V Jan Mayen, sta. 362–05, 80°52.4′ N, 014°27.9′ E, 1234 m, 07 September 2005: 1 paratype, leg. W. Vader, TSZCr 14361; Norwegian Sea, off Northern GoogleMaps Norway, R / V Johan Ruud , sta. 1130–79, 70°52′ N, 015°23′ E, 2000 m, epibenthic sledge, 19 September 1979: 1 paratype, leg. T GoogleMaps . Holthe , TSZCr 14910; Håkjerringdjupet, off Northern Norway, R / V Johan Ruud , sta. 1122–79, 70°43′ N, 016°56′ E, 740 m, 18 August 1979, triangular dredge: three paratypes of which one is an adult male, leg. T GoogleMaps . Holthe , TSZCr 11983; Norwegian Sea, off Northern Norway, R / V Johan Ruud , sta. 1132–79, 69°56′ N, 015°46′ E, 2500 m, mud with foraminifera, 20 August 1979, epibenthic sledge: 1 paratype, leg. T GoogleMaps . Holthe , TSZCr 11795; Norwegian Sea, off Northern Norway, Lagnesegga , R / V Johan Ruud 1214–82, 68°26′ N, 014°32′ E, 1750 m, epibenthic sledge, 26 August 1982: 1 medium sized paratype, leg. T GoogleMaps . Holthe , TSZCr 11810 .

Description

Rostrum well developed, narrow, with acute tip. Eye absent.

A1. Major flagellum with 33 articles in male and in female; accessory flagellum with 22 articles in male and in female.

A2. Fourth article of peduncle with short slender ventrolateral and dorsomedial spines; fifth article without spines; flagellum with 23 articles in male and 26 in female.

Epistome rounded, not protruding in lateral view.

Md. Left lacinia mobilis large with anterior margin with five rounded teeth; right lacinia mobilis slightly smaller than left, with anterior margin almost smooth, vaguely sinuate and with one large lateral triangular tooth; some spines of incisor process bifid, distal one of normal stoutness; article one of palp shorter than article two (ratio of length article one: article two = 0.82); article one 4.91 times as long as wide; article two with setae on tip and all along distal half, 7.30 times as long as wide; article three 4.77 times as long as wide, 0.57 times as long as article two.

Mx1. First article of palp with two well-developed setae; second article of palp with 17 strong setae (forming seven transverse rows of one to four setae) on upper margin, 15 slender spines on ventral and apical margins and 13 facial setae; outer plate with 10 slender weakly denticulate spines; inner plate with a single seta on tip.

Mx2. Outer plate with about nine short and medium-sized setae on upper margin.

Mxp. Palp with dactylus fairly stout, with ventral margin distinctly convex, 0.57 times as long as article three; article three of palp with three transverse rows of thin dorsomedial setae; outer plate with 16 to 17 closely spaced spines on medial border (these spines are of normal length and stoutness), and about nine strong medioventral setae; inner plates with five well-developed anterior spines and 20 marginal and submarginal strong but non-spiniform setae.

Gn1. Coxa broadly triangular, with distinctly concave posterior border, with small anterior and posterior tooth; merus and carpus with confluent groups of setae; merus with small acute distal tooth; tip of carpus almost reaching propodal group of strong spines (as seen in outer view); propodus 1.85 times as long as wide; group of spines on the proximal 0.21 of propodus (emergence of most distal spine on outer side used as reference point); one of these spines is rather long; palm border forming a regular curve, without teeth, with hooked spines of outer row narrowly spaced (about 99 hooked outer spines); dactylus with five teeth.

Gn2. Coxa triangulo-elliptic with small anterior and posterior teeth; merus and carpus with confluent groups of setae; merus with small acute distal tooth; tip of carpus overreaching propodal group of strong spines in female but not in male; propodus 1.92 (female) or 1.72 (male) times as long as wide; group of spines on the proximal 0.32 of propodus in both sexes (emergence of most distal spine on outer side used as reference point) [spines rubbed off in illustrated female]; these spines are short and arise from a strong protrusion; palm border curved and convex in female but almost straight (barely convex) and curving abruptly near the tip in male, without teeth; medial setae of palm short, with hooked spines on outer row in females; these spines are narrowly spaced (71 hooked spines); dactylus of normal width, with five (male) or eight (female) teeth and toothed on half of length.

P3. Coxa quadrato-elliptic, rather narrow, with small posterior tooth and weak anterior notch; merus 1.62 times as long as carpus and 1.20 times as long as propodus; carpus 3.95 times as long as wide; propodus 6.73 times as long as wide; dactylus not very long, rather stout with its two borders slightly curved, 0.63 times as long as carpus and 0.49 times as long as propodus; posterior border of merus with three groups of one or two short setae; carpus with five groups of one or two long setiform spines on posterior border (longest spine in distal group; this spine is 1.64 times as long as width of carpus and 0.42 times as long as carpus length), and one shorter setiform spine paired with a tiny setule at the tip of anterior border; propodus with eight groups of one or two setiform spines and a tiny distal stout spine on posterior border (longest setiform spines 1.8 times as long as width of propodus and 0.27 times as long as length of propodus); anterior border of propodus with distal group of four welldeveloped spiniform setae and three groups of one or two setiform spines more proximally (one rubbed off but indicated by a scar on illustrated specimen).

P4. Coxa of normal width (1.22 times as long as wide), with anterior and posterior borders nearly parallel, with ventral border almost straight, with three normally developed teeth on posterior border and one normally developed anteroventral tooth; merus 1.63 times as long as carpus and 1.29 times as long as propodus; carpus 3.85 times as long as wide; propodus 7.58 times as long as wide; dactylus not very long, rather stout with its two borders slightly curved, 0.62 times as long as carpus and 0.47 times as long as propodus; posterior border of merus with two isolated setae; carpus with four groups of one or two long setiform spines on posterior border; propodus with eight groups of one to three spines (the longest are setiform) on posterior border (longest setiform spines 2.23 times as long as width of propodus and 0.30 times as long as length of propodus); anterior border of propodus with distal group of seven well-developed spiniform setae and three groups of one or two setiform spines more proximally.

P5. Basis very narrow (2.25 times as long as wide), anteriorly distinctly and regularly convex, posteriorly straight; anterior border with conical spines, posterior border with 10 (male) to 11 (female) distinct but not especially strong, non-erect teeth (posterodistal angle not included), tip of distal tooth close to or overreaching posterodistal angle, distal border nearly straight (slightly concave) (junction between posterior and distal borders forming a right angle) and not at all produced into a lobe; merus with anterior group and posterior groups of very short spines; carpus with three anterior groups of short slender spines, one group intermixed with short setae and no posterior spines (except apical group); carpus 0.63 times as long as merus; propodus with five anterior short slender spines each followed by a tuft of moderately long setae; propodal apical tuft of setae well developed; dactylus distinctly curved and fairly stout, 0.27 times as long as propodus.

P6. Basis very narrow (2.19 times as long as wide), anteriorly slightly convex and posteriorly straight; anterior border with conical spines, posterior border with posterior border with 10 (male) to 12 (female) distinct but not especially strong, non-erect teeth (posterodistal angle not included), tip of distal tooth close to or overreaching posterodistal angle, distal border nearly straight (slightly concave) (junction between posterior and distal borders forming a square angle) and not at all produced into a lobe; merus with anterior and posterior groups of small spines; carpus with anterior and posterior groups of small spines (some anterior ones intermixed with short setae); carpus 0.68 times as long as merus; propodus with at least four anterior spines (some probably rubbed off) followed by a tuft of moderately long setae; propodal apical tuft of setae well developed; dactylus weakly curved and fairly stout, 0.27 times as long as propodus.

P7. Upper part of posterior border of coxa produced into a tooth; basis proximally expanded, very narrow (1.87 times as long as wide), anteriorly weakly convex and posteriorly slightly concave; anterior border with conical spines, posterior border with seven (male) to 10 (female) distinct teeth (posterodistal angle not included), tip of distal tooth overreaching posterodistal angle, distal border nearly straight (slightly concave) (junction between posterior and distal borders forming a right angle) and not at all produced into a lobe; merus and carpus with rather short anterior and posterior spines; carpus 1.03 times as long as merus; propodus of P7 2.13 times as long as propodus of P6; propodus with nine anterior spinules (most paired with a short seta), and five posteromedial isolated fairly short spines (which are not associated with setae); propodal apical tuft of setae lacking; dactylus nearly straight, distally not notched, fairly slender, short, 0.17 times as long as propodus.

Pleonite 1. Posterodorsal area produced into one large tooth; Ep1 with small posteroventral tooth, with posterior border distinctly convex; without setae.

Pleonite 2. Posterodorsal area produced into one large tooth; Ep2 with small posteroventral tooth, with posterior border slightly convex.

Pleonite 3. Posterodorsal area toothless and deeply notched; Ep3 with small posteroventral tooth (of which the ventral margin is regularly convex), with posterior border straight on all its length and joining the posteroventral tooth, usually (but not always) after forming a shallow notch (a minute tooth sometimes present just above this notch).

Urosomite 1. with crest-like carina, posteriorly terminated into a strong posterodorsal tooth obliquely pointing upwards; ventrolateral border with one or two spines; peduncle of U1 with nine to 11 dorsolateral spines: eight to 10 regularly spaced and short and rather slender ones spread along length of peduncle and a long and strong distal one (longer or shorter than distal tooth), with eight dorsomedial spines (which are slender and fairly short) regularly spaced all along its length; outer ramus with 15 short and rather slender outer spines and 12 short medial spines; inner ramus with seven very short spines on outer border and nine short spines on medial border.

Urosomite 2. Dorsal border forming a large triangular tooth pointing obliquely upwards; peduncle of U2 with seven regularly-spaced and fairly short (except the distal one which is long) slender dorsolateral spines, with four dorsomedial spines; outer ramus with seven to eight short outer spines and four short medial spines; inner ramus with five short spines on outer border and seven short to well-developed spines on medial border.

Urosomite 3. A pair of long posterodorsal styliform spines; lateral projection usually produced into a tooth; outer ramus of U3 without spines; inner ramus with three to four very short and rather stout spines on outer side, with four or five very short and stout spines on medial side.

Telson. Cleft on 0.68 of its length; medial tooth of each lobe reaching 0.42 of outer tooth; inter-teeth spine reaching tip of outer tooth, 0.19 times as long as telson; apical teeth of telson without setae.

Colour pattern

Yellowish semitransparent (observations by the second author).

Size

Up to 32 mm.

Depth range

740 to 2500 m (present material).

Distribution

Svalbard (present material; (?) Schellenberg, 1925 as L. fissicornis : specimen without posterodorsal tooth on the third pleonite collected at 1000 m), Norwegian Sea off Northern Norway (present material), (?) Jan Mayen Island, (?) between Jan Mayen Island and the Faeroes ( Stephensen, 1931 as L. fissicornis : specimens without posterodorsal tooth on the third pleonite collected below 885 m).

Etymology

From the Latin noun caligo, -inis, which means obscurity or darkness. The name, which is a genitive, alludes to the darkness of the deep sea, which is the habitat of the species.

Remarks

The depth range of the aforementioned specimens of Schellenberg (1925) and Stephensen (1931) strongly suggests they are L. caliginis sp. nov. and not L. fissicornis , which is also devoid of a posterodorsal tooth on the third pleonite. However, a confirmation of this assumption is impossible without a direct examination of the specimens. It is also likely that the deep-water material from the Norwegian Sea recorded by G.O. Sars (1886) includes specimens of L. caliginis sp. nov., but this cannot be certified because he gives no information on their morphology. It is also possible that the deepsea samples of L. fissicornis from East Greenland recorded without taxonomic comment by Brandt (1997) belong to L. caliginis sp. nov. On the other hand, her material from the continental shelf could belong to a different species, possibly true L. fissicornis .