Liouvillea rocagloria, Coleman & Krapp-Schickel & Häussermann, 2022

Coleman, Charles Oliver, Krapp-Schickel, Traudl & Häussermann, Vreni, 2022, Amphipod crustaceans from Chilean Patagonia, European Journal of Taxonomy 849 (1), pp. 1-57 : 40-41

Liouvillea rocagloria sp. nov.

urn:lsid:zoobank.org:act:E11887DA-7761-495E-A7CD-776CD936F88C

Figs 24–26 , 30g –h

Diagnosis

Antenna 1 much longer than body and than antenna 2, mandible last palp article subequal to second article. Maxilla 1 inner lobe subequal to outer one. Gnathopod coxae 1–2 much deeper than wide. Gnathopod 1 carpus longer than ischium and merus combined, propodus subequal to carpus, dactylus about as long as palmar margin, basis with short setae. Gnathopods subequal in shape, gnathopod 2 propodus rectangular and subequal to carpus length, propodi of both gnathopods subequal. Telson cleft about ⅔ of length.

Etymology

The species name (noun in apposition) is in reference to the type locality, i.e., Roca Gloria, Aysén, Chile.

Material examined

Holotype

CHILE • 1 ♀ (8 mm), slide in Faure’s medium; Roca Gloria; -45.61152778°, -74.47819444°; 15 m depth; 5 Apr. 2014; 92HF21; on Hydrozoa ; colour white; MVRCr 7734 ( Figs 24–26 ).

Paratypes

CHILE • 10 specs (4–8 mm); same collection data as for holotype ; ZMB 34213 .

Additional material

CHILE • 6 specs (4–7 mm); Canal Ultima Esperanza SE, -44.5909°, -73.34921667°; 26 m depth; 10 Apr. 2014; 399HF21; on Swiftia sp. (gorgonian octocoral) together with Ligulodactylus macrocheir ( Schellenberg, 1926) ; ZMB 34215 • 2 specs (4 mm); Isla Porcia NE ; -47.9175°, -74.51356667°; 15– 20 m depth; 19 Apr. 2015; 121HF24; on Hydrozoa ; body colour clear red; ZMB 34214 • 2 specs (4 mm); Isla Waller ; -46.76475°, -75.23121667°; 20 Apr. 2015; 143HF24; on Bryozoa; body colour whitish with red tips; ZMB 34216 • 1 spec. (6 mm); Estero Millabu ; -45.757617°, -74.551600°; 7.4 m depth; 20 Nov. 2011; HF11CO17; on hydrozoan on a rock; body colour whitish; ZMB 34211 • 1 juv. spec.; Isla Fronton ; -46,7233666°, -75.2558°; 10 m depth; 20 Apr. 2014; 147HF24; on Hydrozoa; ZMB 34212 .

Description

Holotype

BODY. Last pereon and first two pleon segments each with one dorsal tooth, in smaller specimens not much developed.

HEAD ( Fig. 24a ). Shorter (vs longer in Liouvillea oculata Chevreux, 1912 ) than 3 first pereonites together.

HEAD APPENDAGES. Antenna 1 ( Fig. 24a–b ) much longer than body and than antenna 2; accessory flagellum rudimentary. Antenna 2 ( Fig. 24a ) subequal to body length. Mandibles ( Fig. 24c–d ) cutting edge with 6 spines, last palp article subequal to second article. Maxilla 1 ( Fig. 24e ) inner lobe subequal to outer, both with ciliated setae. Maxilla 2 ( Fig. 24f ) inner plate slightly shorter than outer, with a row of facial setae. Maxilliped ( Fig. 24g ) outer plate reaches about middle of second palp article; palp article 3 with prolongation.

PEREON. Gnathopod coxae 1–2 much deeper than wide, broadened anterodistally. Gnathopod 1 ( Fig. 24h ) carpus longer than ischium and merus combined; propodus subequal to carpus, subrectangular, distally somewhat widened; palmar corner blunt, more than 90 degrees, dactylus curved, about as long as palmar margin (vs shorter); basis with short setae on anterior and posterior margin. Gnathopod 2 ( Fig. 24i ) shape similar, subequal in length to gnathopod 1; propodus rectangular, palmar corner with nearly right angle; propodus subequal to carpus, length of propodus of gnathopod 2 subequal to the one of gnathopod 1. Pereopods ( Fig. 25a–b, d–f ) 3–7 dactyls long, about half length of propodus. Pereopods 5–7 basis oval, crenulated posteriorly (vs smooth in Liouvillea oculata ); merus posteriorly clearly lengthened (vs only scarcely lengthened in Liouvillea oculata ), subequal in length with carpus; propodus ratio length to width about ⁴/5 (vs much more slender in Liouvillea oculata ).

PLEOSOME AND UROSOME. Epimeron 3 ( Fig. 25g ) with small distal tooth. Uropod 1 ( Fig. 26a ) outer ramus ¾ of length of inner one (vs half as long as inner one in Liouvillea oculata ), peduncle subequal to inner ramus. Uropod 2 ( Fig. 26b ) outer ramus about half length of inner one, peduncle shorter than inner ramus. Uropod 3 ( Fig. 26c–g ) peduncle about half length of outer ramus, with acute prolongation on inner side, about as long as outer margin of peduncle; outer ramus very robust, with strong spines on outer margin; inner ramus in most of the material lost, but when present, longer than outer one, lanceolate, also beset with lots of spines on both margins ( Chevreux (1912) writes for Liouvillea oculata : “the inner ramus is represented by a long spiniform process of the peduncle, without traces of articulation”). No ciliated setae found (vs ciliated setae together with spines in Liouvillea oculata ). Telson ( Fig. 26h ) distally rounded, cleft for about ⅔ of length (vs ¼ of length in Liouvillea oculata )

Distribution

Only known from the type locality.

Depth range

7.4– 26 m.

Type locality

Roca Gloria, Aisén, Chile.

Type specimen location

MVRCr 7734 (holotype), ZMB 34213 (paratypes).

Remarks

The length of this new species is smaller than the hitherto only known species of this genus, Liouvillea oculata Chevreux, 1912 , which is described with 9 mm by Chevreux (1912) and with 11 to even 19 mm by Thurston (1974). Antenna 1 is longer than the body (vs as long as), gnathopod 1 propodus subequal to (vs longer than) carpus, dactylus about as long as palmar margin (vs shorter), basis with short vs long setae on both margins. Both gnathopods are subequal in length, while gnathopod 2 is longer in Liouvillea oculata . Gnathopod 2 propodus is rectangular (vs much wider), subequal to carpus (vs clearly longer), length of gnathopod 2 propodus subequal to the one of gnathopod 1 (vs much longer). For uropod 3 Chevreux reports “the inner ramus is represented by a long spiniform process of the peduncle, without traces of articulation”. No ciliated setae found here, while ciliated setae together with spines can be found in Liouvillea oculata . The telson in the present species is cleft about ⅔ of length (vs ¼ of length).

Figures

Fig. 24. Liouvillea rocagloria sp. nov., holotype, ♀, 8 mm (MVRCr 7734). a. Right side of head with antenna 1 and 2. b. Articles 1–2 of antenna 1. c. Mandible. d. Mandible palp. e. Maxilla 1. f. Maxilla 2. g. Maxilliped. h. Gnathopod 1. i. Gnathopd 2. Figure not scaled.

Fig. 25. Liouvillea rocagloria sp. nov., holotype, ♀, 8 mm (MVRCr 7734). a. Pereopod 3. b. Pereopod 4. c. Epimerial plate 2. d. Pereopod 5. e. Pereopod 6. f. Pereopod 7. g. Epimeral plate 3. Figure not scaled.

Fig. 26. Liouvillea rocagloria sp. nov., holotype, ♀, 8 mm (MVRCr 7734). a. Uropod 1. b. Uropod 2. c. Uropod 3. d. Uropod 3. e. Margin of ramus of uropod 3. f. Uropod 3 ramus. g. Uropod 3 (partially) different aspect. h. Telson. Figure not scaled.

Fig. 30. In vivo photos of some of the described amphipods. a. Sunamphitoe femorata (Krøyer, 1845). b. Numerous specimensof Caprellacf.equilibraSay, 1818,on thehydrozoanHalopteris schucherti Galea, 2006. c. Habitat of Leucothoe kawesqari Esquete & Aldea, 2015, on sponge. d. Epimeria (Metepimeria) acanthurus (Schellenberg, 1931). e–f. Podocerus cf. danae (Stebbing, 1888). g. Liouvillea rocagloria sp. nov. h. Habitat of Liouvillea rocagloria sp. nov. Photos: Iván Hinojosa (a); V. Häussermann & G. Försterra (b, d, h); G. Försterra & V. Häussermann (c, e–g).