Halirages spongiae, Lörz & Nack & Tandberg & Brix & Schwentner, 2024

Lörz, Anne-Nina, Nack, Madita, Tandberg, Anne Helene S., Brix, Saskia & Schwentner, Martin, 2024, A new deep-sea species of Halirages Boeck, 1871 (Crustacea: Amphipoda: Calliopiidae) inhabiting sponges, European Journal of Taxonomy 930, pp. 53-78 : 59-66

Halirages spongiae sp. nov. Lörz, Nack & Tandberg

urn:lsid:zoobank.org:act:BEBF5415-BCDF-4CD2-8BD3-A89F20CB7067

Figs 1–9 , Table 1–3

Etymology

‘ Spongia’: Latin for ‘sponge’. The name originated from the habitat of the holotype. It was found on a sponge in an abyssal plain east of Iceland.

Type material

Holotype ICELAND • ♂, 27.9 mm; North-Atlantic; IceAGE 3 cruise, SO276 station 37; 66°03.094′ N, 004°00.122′ W; depth 3674 m; 1 Jul. 2020; collected with the slurp-gun of the ROV from the sponge Caulophacus arcticus (Hansen, 1885) ; NHMW-CR-28125 .

Paratypes

ICELAND • 1 ♂, 41.2 mm; same collection data as for holotype; NHMW-CR-28126 • 1 ♂, 40.3 mm; same collection data as for holotype; NHMW-CR-28127 • 1 ♂, 37.4 mm; same collection data as for holotye; ZMH K-64213 • 1 ♂, 45.0 mm; ZMH K-64214 • 1 ♂, 41.1 mm; ZMH K-64215 .

Description

MEASUREMENTS. Large animals up to 4.5 cm with whiplike antennae as long as body. Body length. 27.9–44.9 mm (average length of types 34.7 mm).

DORSAL ORNAMENTATION ( Figs 2–3 ). Pereionite 7 and pleonites 1–2 each with strong posterodorsal tooth; pereionite 6 without posterodorsal tooth.

HEAD ( Fig. 4A ). Rostrum weak; anterior lobe of head blunt and square (corners rounded), followed posteriorly by narrow sinus; ventral lobe of head pointed, pointing anteriorly, smooth-edged, and not toothed; eye large and subreniform, with defined ommatidia, no pigmentation evident after fixation in alcohol.

ANTENNAE ( Figs 2 , 4A–C ). Antennae 1 slightly longer than Antenna 2, flagella long. Peduncular articles of antenna 1 progressively shorter, flagellum with more than 150 articles; Antenna 2 article 1 of peduncle with 2 normally developed ventrolateral distal teeth, articles 4 and 5 subequal, flagellum with approximately 200 articles.

LOWER LIP ( Fig. 4D ). With narrow rounded mandibular processes, inner lobes present, broad outer lobes.

UPPER LIP ( Fig. 4E ). Apically rounded, entire.

MANDIBLE ( Fig. 4F ). Incisor process with 3 very blunt teeth; molar ridged, lateral margin, with a row of narrow spines, left molar with anterolateral longer seta; palp article 1 short, with one stronger seta and three short setae; articles 2 and 3 equal in length; article 2 strong, with a row of setae; article 3 falciform, with row of setae, with apical tuft of setae.

MAXILLA 1 ( Fig. 4H ). Inner plate with 13 pinnate spines, length varying making uneven fringe; outer plate with six cuspidate spines apically; palp well developed, with strong article 2, article 2 with row of long styliform marginal spines and setae (most forming a row) with three longer anterodistal spines (uppermost arising medially).

MAXILLA 2. Damaged.

MAXILLIPED ( FIG. 4G ). Maxilliped with inner and outer plates broad and subequal; palp of four articles, article 4 shorter than article 3, plates and all article of palp except for dactylus setose.

PEREIOPOD 1 ( Fig. 5A ). Coxa with anteroventral corner pointing forward, ventral margin with about 10 weak crenulations; carpus longer than wide, as long as basis, anterior margin smooth, posterior margin setose; propodus longer than wide and shorter than carpus; palm sharply dentate, with row of thin setae; dactylus dentate along entire posterior margin.

PEREIOPOD 2 ( Fig. 5B ). Coxa quadrate, with 10 weak crenulations along ventral margin; carpus about 5 × as long as wide, as long as basis, plumose setae at distal margin; palm sharply dentate, with row of thin setae; dactylus dentate along entire posterior margin; gill length of basis.

PEREIOPOD 3 ( Fig. 5C ). Coxa quadrate with about 10 weak to almost indistinct crenulations; leg only weakly setose; basis distinctly concave anteriorly and distinctly convex posteriorly, with setae on both margins.

PEREIOPOD 4 ( Fig. 5D ). Coxa wider than long and merging posteriorly into blunt slightly triangular projection, with ventral margin with 10 weakly developed serrations; leg slightly tapering, slightly longer than pereiopod 3; basis concave anteriorly and convex posteriorly, with setae on both margins.

PEREIOPOD 5 ( Figs 2 , 5E ). Pereiopod 5<pereiopod 6<pereiopod 7; posterior lobe of coxa distinctly longer than anterior lobe; leg weakly setose; basis elliptic, anterior margin with spines and sparse. thin setae, distally without tooth, posterior margin with very low to barely discernible crenulations, posterodistal margin rounded and smooth.

PEREIOPOD 6 ( Figs 2 , 5F ). Posterior lobe of coxa distinctly longer than anterior lobe; basis elliptic, longer than wide, anterior margin with spines and sparse thin setae, posterior margin with indistinct to very low crenulations, posterodistal margin rounded and smooth.

PEREIOPOD 7 ( Figs 2 , 5G ). Coxa rather small and elliptic in shape; leg weakly setose; basis with anterior and posterior margins straight and converging toward apex, longer than wide, anterior margin with five spines and few thin setae, posterior margin with 18 spines, posterodistal margin with three spines; transition between posterior and posterodistal margins obtusely angular.

EPIMERAL PLATE 1 ( Fig. 6A ). With four isolated spines, posterior border smooth and rounded with minuscle tooth.

EPIMERAL PLATE 2 ( Fig. 6B ). With five isolated spines, with very weak but acute posteroventral tooth, posterior border straight and smooth.

EPIMERAL PLATE 3 ( Fig. 6C ). With three isolated spines, weak posteroventral protrusion, posteroventral edge between the protrusion and posteroventral tooth straight and weakly crenulate.

UROPOD 1 ( Fig. 6D ). Peduncle with dorsolateral and dorsomedial rather slender and irregularly large spines; outer ramus with dorsolateral spines of different sizes, with dorsomedial and apical spines; inner ramus as long as peduncle, with dorsolateral spines, with dorsomedial rather slender and very irregularly large spines; medial margin of inner ramus finely serrate. Apical seta on both rami stronger than other seta of the rami.

UROPOD 2 ( Fig. 6E ). Peduncle with dorsolateral and dorsomedial rather slender, irregularly sized spines; outer ramus with dorsolateral, irregularly sized spines; inner ramus with dorsolateral and dorsomedial spines; medial margin of inner ramus minimally toothed.

UROPOD 3 ( Fig. 6F ). Peduncle with eight distolateral dorsal spines; inner ramus almost twice length of outer ramus; outer ramus with several lateral irregularly sized spines (most small and slender); inner ramus, without distinct bulge, with several lateral spines.

TELSON ( Fig. 6G–H ) Triangular, with convex margin, distally tridentate, without cusp.

COLOUR PATTERN ( Fig. 2 ). Body uniformly light pink, mouthparts and pereiopods 1 and 2 distinctly more reddish, eyes white. In alcohol, red pigment remains longer on mouthparts and pereiopods.

Distribution

East off Iceland, 3674 m (currently known only from the type locality).

Remarks

Halirages spongiae sp. nov. Lörz, Nack & Tandberg is morphologically closest to H. cainae d’Udekem d’Acoz 2012 and H. qvadridentatus G.O. Sars, 1877 , but differs in the following characteristics (see also Table 2 ): the dorsal ornamentation of H. spongiae and H. cainae show teeth on pereonite 7, pleonites 1 and 2, whereas H. qvadridentatus shows the additional tooth on pereonite 6. The anteroventral corner of coxa 1 forms a square in H. cainae while in H. spongiae and H. qvadridentatus the corner is projected anteriorly. In addition, the species differ in their ornamentation of posterior border of basis of P7; in H. cainae this is distinctly serrate whilst in H. spongiae only weakly serrate. Halirages spongiae bears a small protrusion on the posterior border of epimeral plate three, whereas this is absent in H. cainae and H. qvadridentatus . Also, the tip of the telson differs; in H. cainae the telson forms a single tooth at the tip, while the telson of H. qvadridentaus and H. spongiae is tridentate.

Freshly caught H. cainae is dark red ( d’Udekem d’Acoz 2012: fig. 1) whereas live H. spongiae sp. nov. Lörz, Nack & Tandberg is coloured light pink ( Fig. 2 ).

Figures

Fig. 1. Examples of ROV Kiel 6000 images at 3500 m depth northwest of Iceland at a water temperature of minus 1°C. A–D. Sponge aggregations of Caulophacus arcticus (Hansen, 1885) provide a habitat for caridean shrimp (Bythocaris cf. leucopis G.O. Sars, 1879) and Halirages spongiae sp. nov. Lörz, Nack & Tandberg. E–F. On a rusted can (rubbish) during the same transect the same amphipod was found, next to anemones and Pycnogonida.

Fig. 2. Photos of live Halirages spongiae sp. nov. Lörz, Nack & Tandberg taken on board shortly after sampling. A. Holotype, ♂ (NHMW–CR-2812). B. Paratype, ♂ (ZMH K-64213). Scale bars = 1 cm.

Fig. 3. Habitus of Halirages spongiae sp. nov. Lörz, Nack & Tandberg, holotype, ♂ (NHMW- CR-28125). Scale bar = 5 mm.

Fig. 4. Halirages spongiae sp. nov. Lörz, Nack & Tandberg, holotype, ♂ (NHMW-CR-28125). A. Head and beginning of left antennae. B. Antenna 1. C. Antenna 2. D. Labium. E. Labrum. F. Mandible. G. Maxilliped. H. Maxilla 1. Scale bars: A = 2 mm; B–C, G = 1 mm; D–F, H = 0.5 mm

Fig. 5. Halirages spongiae sp. nov. Lörz, Nack & Tandberg, holotype, ♂ (NHMW-CR-28125). A. Pereiopod 1. B. Pereiopod 2. C. Pereiopod 3. D. Pereiopod 4. E. Pereiopod 5. F. Pereiopod 6. G. Pereiopod 7. Scale bars = 1 mm.

Fig. 6. Halirages spongiae sp. nov. Lörz, Nack & Tandberg, holotype, ♂ (NHMW-CR-28125). A. Epimeral plate 1. B. Epimeral plate 2. C. Epimeral plate 3. D. Uropod 1. E. Uropod 2. F. Uropod. 3. G. Telson dorsal view. H. Telson lateral view. Scale bars = 1 mm.

Fig. 7. Halirages spongiae sp. nov. Lörz, Nack &Tandberg,paratype, ♂(ZMH K-64213).A. Pereiopod 1, palm. B. Defining characters such as the posterodorsal ornamentation and pleon, the extension of the first coxa and the crenulation of the third epimeral plate mentioned in the text and Table 2 discussing the Halirages Boeck, 1871 OTUs. Scale bars: A = 100 μm; B = 1 cm.

Fig. 8. Distribution of Halirages Boeck, 1871, opperational taxonomic units discussed in the present paper. Circles indicate specimens used in phylogenetic analysis, stars indicate type localities for the indicated taxa. (Apart from Halirages aff. fulvocinctus, from Canada, all specimens have been sampled by the authors.)

Fig. 9. Phylogenetic analyses ofHalirages Boeck, 1871.A. COI.B. 28S.C. COI+28S (including only individuals for which both genes were available). D. COI+28S (including all specimens). The depicted topologies are based on the Bayesian inference analysis. Bayesian posterior probabilities and bootstrap support from the Maximum Likelihood analyses are shown for each node.