Chauliopleona paradoxa, Guerrero-Kommritz, 2005

Guerrero-Kommritz, Jürgen, 2005, Review of the genus Chauliopleona Dojiri and Sieg, 1997 (Crustacea, Peracarida, Tanaidacea) and description of three new species, Journal of Natural History 39 (16), pp. 1177-1210 : 1199-1203

Chauliopleona paradoxa n. sp.

( Figures 11 , 12 )

Material examined

HOLOTYPE: non-ovigerous female, ZMH K-40232, RV Sonne , Discol station 559, 7 ° 7.509S, 88 ° 27.019W, 4171 m, KG 1519, 20 January 1996 . PARATYPES: 26 non-ovigerous females; ZMH K-20233, RV Sonne , Discol station 515 (1) , ZMH K-40234, RV Sonne , Discol station 517 (1) , ZMH K-40235, RV Sonne , Discol station 527 (1) , ZMH K-40236, RV Sonne , Discol station 529 (2) , ZMH K-40237, RV Sonne , Discol station 534 (1) , ZMH K- 40238, RV Sonne , Discol station 534 (2) , ZMH K-40239, RV Sonne , Discol station 539 (2) , ZMH K-40240, RV Sonne , Discol station 540 (3) , ZMK K-40241, RV Sonne , Discol station 544 (4) , ZMH K-40242, RV Sonne , Discol station 555 (1) , ZMH K-40243, RV Sonne , Discol station 556 (1) , ZMH K-40244, RV Sonne , Discol station 565 (1) , ZMH K- 40245, RV Sonne , Discol station 574 (3) , ZMH K-40246, RV Sonne , Discol station 579 (1) , ZMH K-40247, RV Sonne , Discol station 585 (1) , ZMH K-40248, RV Sonne , Discol station 597 (1) .

Diagnosis

Cheliped dactylus with dorsal crenulation, carpal shield well developed. Dactylus of pereopods 4–6 with prominent spines.

Description

Body ( Figure 11 a–c). About seven times as long as broad, cylindrical, about 1–4.06 mm in length. Cephalothorax about 1.3 times as long as broad. Ventral groove around cheliped insertion. Pereonites 2 and 3 longest and equal in length, 4 and 5 equal in length, 6 shortest. Pereonite 1 widest. Pleon longer or as long as cephalothorax, pleonites subequal in length. Pleotelson pentagonal.

Antennule ( Figure 11d ). Article 1 longest with two small and one long simple setae. Article 2 with one long and one short simple setae. Article 3 with a simple seta. Article 4 with four long and one short simple terminal setae.

Antenna ( Figure 11e ). Article 1 short, naked. Article 2 with one simple dorsodistal seta. Article 3 with one long simple dorsodistal seta. Article 4 longest with two long simple setae distally. Article 5 with one terminal seta. Article 6 shortest with two short and three long simple setae.

Labrum ( Figure 11i ). Hood-like, with a row of long setules laterally and short setules distally.

Mandible ( Figure 11j ). Well calcified and sclerotized on incisive margins, molar process developed bearing about 10 terminal spinules.

Maxillule ( Figure 11l ). Endite with setules, with five long setulose and two long simple spines and one short terminal one. Palp with two distal setae.

Maxilla ( Figure 11m ). Rectangular with one row of setules distally.

Labium ( Figure 11k ). Composed of two triangular lobes with one distal seta.

Maxilliped ( Figure 11o ). Endites naked. Palp article 1 naked. Article 2 with one outer and three curved spiniform setae. Article 3 with three inner curved spiniform setae. Article 4 with two short inner spiniform setae and four terminal spiniform setae.

Epignath ( Figure 11m ). Falciform.

Cheliped ( Figures 11f , 15f ). Posterior part of basis tapering distally. Merus with one simple seta. Carpus 1.6 times as long as broad, with one ventral simple seta and two dorsal simple setae, one rounded protuberance near attachment of propodus. Carpal shield well developed. Propodus twice as long as broad with two or three teeth on fixed finger, three dorsal and two ventral simple setae. Dactylus with a fine crenulated dorsal border.

Pereopod 1 ( Figure 12a ). Coxa without setae. Basis naked. Ischium with one simple seta. Merus with one long spiniform seta. Carpus with two long spiniform setae and ventral row of spinules. Propodus with one short terminal spiniform seta and many small spinules ventrally. Dactylus short, about half the length of unguis. Unguis pointed.

Pereopod 2 ( Figure 12b ). As pereopod 1, except one long simple seta on basis.

Pereopod 3 ( Figure 12c ). As pereopod 2, except with three long spiniform setae on carpus; carpus and propodus with few spinules ventrally or smooth.

Pereopod 4 ( Figure 12d ). Basis with two setulose setae. Ischium with one simple seta. Merus with two short spiniform setae. Carpus with three spiniform setae. Propodus with three long and one short spiniform setae. Dactylus long with ventral groove bordered by proximally directed spines. Unguis pointed.

Pereopod 5 ( Figure 12e ). As pereopod 4, except basis naked, dactylus with more prominent and longer spines. Unguis sharp.

Pereopod 6 ( Figure 12f ). As pereopod 5, except carpus with small lateral spines, propodus with five short terminal spiniform setae.

Pleopods ( Figure 11g ). Endopod with one long simple seta at attachment to basis and seven simple setae distally. Exopod with six distal simple setae.

Uropods ( Figure 11h ). Basal article long, naked. Exopod shorter than article 1 of endopod, of two articles: article 1 longest, with a lateral simple seta, article 2 with one short and one long simple terminal seta. Endopod article 1 with two small simple terminal setae, article 2 with four long and one short simple terminal setae.

Type locality

Peru abyssal plains, Discol , RV Sonne, station 559, 7 ° 7.509S, 88 ° 27.019W, 4171 m, KG 1519, 20 January 1996 .

Etymology

The name refers to the fact that this species is a ‘strange’ C. hastata with some highly variable characters making it difficult to identify.

Remarks

This species has a very wide morphological variability. The posteriorly directed ventral apophysis is very variable and may be very small to very large. The same can be recognized in other characters, such as dentition of the fixed finger of the chela, that varies from one to three teeth. The crenulation on the finger is in some individuals very weak and in others very prominent.

Figures

Figure 11. Chauliopleona paradoxa n. sp. (a–i) ZMH K-40236: (a) dorsal view; (b) lateral view; (c) ventral view of cephalothorax; (d) antennule; (e) antenna; (f) cheliped; (g) pleopod; (h) uropod; (i) labrum. (j–n) ZMH K-40235: (j) mandible; (k) labium; (l) maxillule; (m) epignath; (n) maxilla. (o) ZMH K-40236: maxilliped. Scale bars: 1 mm (a–c); 0.5 mm (d–n); 0.1 mm (o).

Figure 12. Chauliopleona paradoxa n. sp., ZMH K-40236. (a) Pereopod 1; (b) pereopod 2; (c) pereopod 3; (d) pereopod 4; (e) pereopod 5; (f) pereopod 6. Scale bar: 0.5 mm.

Figure 15. Chauliopleona chelipeds. (a) Ch. armata; (b) Ch. hastata; (c) Ch. nickeli; (d) Ch. amftae; (e) Ch. amdrupii; (f) Ch. paradoxa; (g) Ch. dentata. The chelipeds are not drawn to the same scale.