Cyclaspis carinobacata, Mühlenhardt-Siegel, Ute, 2008

Mühlenhardt-Siegel, Ute, 2008, The Cumacea of the Red Sea and Gulf of Aden, with the description of four new species and one genus, Zootaxa 1828, pp. 1-17 : 10-14

Cyclaspis carinobacata sp. nov.

( Figs 7 –8 )

Type material. Holotype: subadult male, ZMH: K 41946 6 March 1987; type locality: Bab el Mandeb, 12°21.4'N 43°26.9'E, 45 m depth, RV Meteor cruise 5/2, station number 236 KD; M. Türkay coll.

Etymology: The new species is named after the carina along the dorsomedian line of the carapace resembling a string of pearls (carina, Lat.: ridge; baca, Lat.: pearl).

Diagnosis. Dorsomedian line of carapace in anterior part with four small teeth ending in a string-ofpearls-like carina; faint ridge running from the dorsomedian quarter anteroventrad. Pleonite 6 tongue-like (pleotelson), with insertion of uropods peduncles under tongue-like prolongation. Terminal seta fused with uni-articulate uropod endopod.

Description. Holotype subadult male ( Fig. 7 ) 4.2 mm total length, carapace 0.3 times total length, dorsomedian line in anterior part with four small teeth ending in a string-of-pearls-like carina; a faint ridge running from the dorsomedian quarter anteroventrad; pseudorostral lobes not meeting in front of ocular lobe; siphonal tube short; ocular lobe long; eyes with lenses. Antennal notch wide; anterolateral tooth strong; anteroventral margin of carapace smooth; integument well calcified.

Five free thoracic segments visible, the first very short, only visible from lateral; pleon 1.4 times longer than carapace and free thoracic segments combined; telsonic segment longer than wide, with distal elongation overlapping insertion of uropod peduncles.

Antenna 1 ( Fig. 8 , A1): relative lengths of peduncle articles 1 to 3: 34/23/43; accessory flagellum less than a quarter in length of basal article of main flagellum. Main flagellum two articulate.

Mouthparts not dissected in order to preserve the holotype.

Maxilliped 2 ( Fig. 8 , Mxp2): B/R ratio 1.1, RLA: 5/24/28 /30/13; basis outer distal corner with five strong simple setae, inner distal corner with long pappose seta, merus with long pappose seta at distal inner corner, carpus and propodus with six pappose setae along inner margin, dactylus as long as terminal seta.

Maxilliped 3 ( Fig. 8 , Mxp3): B/R ratio 1.2, RLA: 20/17/23/24/15; basis and merus with distal prolongation reaching beyond carpus-propodus articulation (prolongations not included in length measurements); basis with two pappose setae at inner distal corner and six pappose setae along outer distal prolongation, ischium with three pappose setae along inner margin, merus with three pappose setae at distal tip of outer prolongation, carpus with three pappose setae along inner margin, propodus with two acuminate setae on inner margin, terminal seta as long as basal part of dactylus; exopod present.

Pereiopod 1 ( Fig. 8 , P1): B/R ratio 0.7, RLA: 6/ 12/21/37 /24; basis with two teeth on distal margin; articles basis to carpus appear serrate due to scaly structure of integument; exopod present.

Pereiopod 2 ( Fig. 8 , P2): basis broken during dissection, RLA: 11/29/15 /14/31; carpus with three strong setae on distal margin, dactylus with three acuminate setae, terminal seta broken, two relatively long and two hair-like setae subterminally.

Pereiopod 3 ( Fig. 8 , P3): B/R ratio 1.0, RLA: 15/23/ 31/20/11; two strong and long acuminate setae at distal corner of carpus, one long acuminate seta at distal corner of basis, ischium, merus and propodus.

Pereiopod 4 ( Fig. 8 , P4): B/R ratio 0.7, RLA: 11/24/33 /19/12; setation similar to pereiopod 3.

Pereiopod 5 ( Fig. 8 , P5): B/R ratio not given, basis broken, RLA: 13/24/ 38/15/10; fewer setae as in pereiopod 3 and 4, but also strong simple seta at distal corner of carpus.

Uropod peduncle 1.4 times longer than pleonite 6 but shorter than endopod. Exopod shorter than endopod; endopod unsegmented, fused with terminal seta, inner margin serrate and with three short strong setae along inner margin ( Fig. 8 , U).

Remarks. The new species is similar to the two species Cyclaspis mexicansis ( Radhadevi & Kurian, 1981) and C. granulata ( Radhadevi & Kurian, 1981) from the Gulf of Mexico because it has well developed ocelli; five free pedigerous segments visible from lateral, the first very short; pereiopod 2 with ischium present; uropod endopod uni-articulate. Only one character, “endopod with terminal and subterminal spines”, does not fit for the new species: the terminal spine of the uropod endopod is fused to the article in the new species.

The uropod endopod in the new species is serrate on the distal inner margin with eight short, stout setae ( C. mexicansis ( Radhadevi & Kurian, 1981) and C. granulata ( Radhadevi & Kurian, 1981) have three long and nine plumose setae along the inner margin, respectively).

Pleonite 6 is tongue-like (pleotelson) in the new species, overlapping the insertion of the uropod peduncles (not overlapping the insertion of the peduncle in the two other species). In C. granulata the pleonite 6 is not produced between the uropods but in C. mexicansis it is.

The dorsomedian line in the new species has in the anterior part four small teeth ending in a string-ofpearls-like carina and a faint ridge runs from the dorsomedian quarter anteroventrad, a character which is not in the two known species.

The basis and merus of maxilliped 3 have distal prolongations as in the two known species, the prolongations do not have plumose setae distally ( C. mexicansis has, C. granulata has at least on the prolongation of the basis).

Figures

FIGURE 7. Cyclaspis carinobacata sp. nov., holotype male, habitus; scale bar: 1 mm.

FIGURE 8. Cyclaspis carinobacata sp. nov., holotype male, appendages; scale bars: 0.1 mm. Scale a: P 1: pereiopod 1, pleonite 5 and 6; U: uropods. Scale b: A 1: antenna 1; Mxp 2: maxilliped 2; Mxp 3: maxilliped 3; P 2: pereiopod 2; P 3: pereiopod 3; P 4: pereiopod 4; P 5: pereiopod 5.