Chauliopleona Dojiri and Sieg, 1997

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 : 1179-1184

publication ID	https://doi.org/ 10.1080/0022293042000197586
persistent identifier	https://treatment.plazi.org/id/03A887A3-0F1E-FFAF-EB8D-FDA59025B673
treatment provided by	Carolina
scientific name	Chauliopleona Dojiri and Sieg, 1997
status

Treatment

Genus Chauliopleona Dojiri and Sieg, 1997 View in CoL

Diagnosis

Pleonite 5 with prominent, posteriorly directed, ventral apophysis. Cheliped insertion via sclerite.

Description

Body cylindrical, long and slender, about seven times as long as broad. Cephalothorax oval or triangular. Eyes and eyelobes absent. Pereon composed of six free pereonites, pereonite 2 longest. Pleon composed of five free pleonites and a pleotelson. Pleonite 5 with a backwarddirected ventral apophysis. Antennule composed of four articles. Antenna composed of six articles. Labrum hood-like with marginal setules. Mandible well calcified, molar process not pointed, turned downward, bearing about 10 pointed spinules. Maxilla rectangular. Maxillule endite with seven or eight terminal spines. Maxilliped basis fused, endites not fused. Cheliped attached laterally by a sidepiece, carpus common with a carpal shield. Pereopods 1–3 with coxa, pereopods 4–6 lacking coxa. Pereopod 1, merus with one spiniform seta and a row of ventral spines or spinules on propodus. Dactylus of pereopods 4– 6 with a ventral groove bordered by spinules, unguis short and pointed. Pleopods biramous. Uropods biramous, exopod shorter than endopod, both composed of two articles each.

Type species

Chauliopleona dentata Dojiri and Sieg, 1997 View in CoL , original designation.

Knoaen species

There are seven known species: Chauliopleona amdrupii ( Hansen, 1913) ; Chauliopleona amftae n. sp.; Chauliopleona armata ( Hansen, 1913) ; Chauliopleona dentata Dojiri and Sieg, 1997 ; Chauliopleona hastata ( Hansen, 1913) ; Chauliopleona nickeli n. sp.; Chauliopleona paradoxa n. sp.

Remarks

Chauliopleona View in CoL is very easy to distinguish from other genera because of its posteriorly directed ventral apophysis on pleonite 5. The genus Portaratrum Guerrero-Kommritz, 2003 View in CoL and the species Leptognathia tuberculata Hansen, 1913 View in CoL do possess a ventral spiniform process on pleonite 5, but this is directed downwards and is not as long as in the species of Chauliopleona View in CoL . The insertion of the cheliped in L. tuberculata View in CoL is a typical Leptognathia View in CoL insertion and that of Portaratrum View in CoL resembles that of Metagathotanais Bird and Holdich, 1988 View in CoL . The genus Scoloura Sieg and Dojiri, 1991 has a posteriorly directed lateral spiniform process on each side of the pleotelson.

Akanthophoreus Sieg, 1986 View in CoL is a very similar genus in many characters but has no ventral posteriorly directed spiniform process on any pleonite or pleotelson.

Chauliopleona dentata Dojiri and Sieg, 1997 View in CoL

( Figures 1 View Figure 1 , 2 View Figure 2 )

Leptognathia armata Schmidt 1999: 40 .

Material examined

PARATYPE: SBMNH 144123 View Materials , non-ovigerous female, 2.0 mm, station 4C, 33 ° 509400N, 118 ° 269220W, 76 m, Santa Monica Bay , California, 8 January 1987 . Other material: ZMH K-40226, one non-ovigerous female, 3.17 mm, RV Victor Hensen, station 1270, 54 ° 559S, 70 ° 459W, 135 m, 21 November 1994 ; ZMH K-40227, one non-ovigerous female, 2.53 mm, RV Victor Hensen, station 1279, 54 ° 469S, 71 ° 089W, 580 m, 21 November 1994 .

Diagnosis

Cheliped dactylus with dorsal crenulation, carpal shield poorly developed. Basal article of uropod with three distal setae.

Redescription

Body ( Figure 1 View Figure 1 a–c). Long, about seven times as long as broad, cylindrical, 2–4 mm in length. Cuticle strong. Cephalothorax about 1.3 times as long as broad, with nearly parallel lateral margins, and abruptly tapering anteriorly. Ventral groove around cheliped insertion. Pereonites 1–4 of similar width, pereonite 5 narrowest, pereonite 6 shortest. Pleon longer than cephalothorax, pleonites subequal, wider than long. Pleotelson pentagonal, apex rounded.

Antennule ( Figure 1d View Figure 1 ). Article 1 longest with one simple and three feathered setae. Article 2 with one long and two simple setae. Article 3 shortest with one simple and two feathered setae. Article 4 with six terminal simple setae.

Antenna ( Figure 1e View Figure 1 ). Article 1 very short. Article 2 as long as broad with one simple thin seta. Article 3 short with one simple seta. Article 4 longest with one short and two long setae as long as article 5. Article 5 with one long terminal seta. Article 6 with four terminal simple setae.

Labrum ( Figure 1i View Figure 1 ). Hood-like with fine marginal setules.

Mandible ( Figure 1j View Figure 1 ). Well calcified and sclerotized on incisive margins, molar process developed, slender, bearing about 10 distal spinules.

Maxillule ( Figure 1l View Figure 1 ). Endite naked with two large setulated, five large simple and one small terminal spines. Palp with one long terminal seta.

Maxilla ( Figure 1m View Figure 1 ). Rectangular, with one row of setules distally. Labium ( Figure 1k View Figure 1 ). Composed of two triangular lobes, with one small terminal seta.

Maxilliped ( Figure 1n View Figure 1 ). Endites with a blunt spine and a simple seta. Palp article 1 naked. Article 2 with one long outer and three curved inner setae. Article 3 with two inner setae. Article 4 with two long and two short inner setae and one short outer seta.

Epignath (not draaen). Falciform.

Cheliped ( Figures 1f View Figure 1 , 15g View Figure 15 ). Basis shorter than carpus, divided unequally by sclerite. Merus with one simple ventral seta. Carpus about 1.7 times as long as broad, with one simple ventral and one small dorsal seta. Carpal shield developed. Propodus with two ventral setae. Fixed finger with three small teeth, cutting edge with one short and two long setae near articulation of finger. Dactylus with crenulations along dorsal margin.

Pereopod 1 ( Figure 2a View Figure 2 ). Coxa with seta. Basis longer than three following articles together. Ischium with one small simple seta. Merus bearing one pinnate spiniform seta. Carpus with one row of ventral spinules and two spiniform setae. Propodus with one ventral row of spinules and curved rows of minute setules, one short dorsal spine and one short spiniform seta. Dactylus short, about half unguis length. Unguis pointed.

Pereopod 2 ( Figure 2b View Figure 2 ). Coxa with seta. Basis longer than three succeeding articles together. Ischium with one small simple seta. Merus with one spiniform seta. Carpus with three spiniform setae. Propodus with one ventral row of spinules and one short spiniform terminal seta. Dactylus and unguis as in pereopod 1.

Pereopod 3 ( Figure 2c View Figure 2 ). As pereopod 2 except merus naked, carpus with two spiniform setae, one long one short; propodus with two short spiniform terminal setae.

Pereopod 4 ( Figure 2d View Figure 2 ). Basis longer than three succeeding articles together. Ischium with simple seta. Merus with two short strong simple setae. Carpus smooth with two strong simple setae. Propodus with one ventral row of small spinules, with three distal long simple strong setae. Dactylus with ventral groove bordered by proximally directed spinules. Unguis short and pointed.

Pereopod 5 ( Figure 2e View Figure 2 ). As pereopod 4, except basis with setulose seta, and carpus with three distal spiniform setae.

Pereopod 6 ( Figure 2f View Figure 2 ). As pereopod 5, except basis naked, and propodus with five terminal spinulose setae.

Pleopods ( Figure 1h View Figure 1 ). Basis sub-triangular. Endopod and exopod similar in shape, with two long terminal plumose setae and about 20 plumose setae each.

Uropods ( Figure 1g View Figure 1 ). Basal article with three small setae near insertion of endopod. Exopod shorter than article 1 of endopod, composed of two articles: article 1 with one simple thin seta, article 2 with one short and one long terminal setae. Endopod composed of two articles: article 1 with one simple and two feathered setae, article 2 with two short feathered and four long simple setae.

Type locality

Station 4C, 33 ° 509400N, 118 ° 269220W, 76 m, Santa Monica Bay, California, 8 January 1987.

Remarks

As C. dentata is currently defined, the distribution is disjunct. It can be found in the Magellan Strait, Beagle Channel and on the coasts of California.

The material examined from the Beagle Channel shows no significant difference from the type material from California. More material from the west coast of South America is needed to clarify whether this species has a such a wide geographical distribution or if there are two different populations, one in California and one in the Beagle Channel. Some features that were described in the original paper could not be seen in the type material. The armature of the antennule and the uropod varies from individual to individual. The feathered setae are not always present .