Heterocuma inerme, Corbera, Jordi, Tirado, Paula & Martin, Daniel, 2005

Corbera, Jordi, Tirado, Paula & Martin, Daniel, 2005, Cumaceans (Crustacea: Peracarida) from the Persian Gulf, Zootaxa 1087, pp. 1-31 : 16-21

Heterocuma inerme sp. nov. ( Figs. 9­11 )

Type material. Assaluyeh, north Nay Band Bay, Persian Gulf. Holotype: 1 ov. female, stn 20, 52°33.763’N 27°20.193’E, 27 m depth, November 2002, ( ICM CUM­ 0052). Allotype: 1 ad. male partially dissected in one slide, stn 25, 52°33.921’N 27°28.547’E, 27 m depth, November 2002, ( ICM CUM­ 0053). Paratypes: 2 juveniles, 3 pread. females, 3 ov. females, 6 pread. males, 1 adult male, same station of holotype, ( ICM CUM­ 0054); 2 pread. females, 5 ov. females, one of them dissected in one slide, 1 adult male, stn 4, 52°33.207’N 27°30.560’E, 21 m depth, November 2002, ( ICM CUM­ 0055).

Other material. Assaluyeh, north Nay Band Bay, Persian Gulf, campaign 1998: 1 pread. female, 1 ov. female, 1 ad. male, stn 4, 52°33.207’N 27°30.560’E, 21 m depth; 1 ovi. female, stn 5, 52°32.959’N 27°30.292’E, 26 m depth; 1 ov. female, 1 ad. male, stn 14, 52°33.591’N 27°29.677’E, 19 m depth; 1 pread. female, stn 18, 52°33.244’N 27°29.406’, 16 m depth; 1 pread. female, 1 ad. male, stn 19, 52°34.003’N 27°29.156’E, 19 m depth; 1 pread. female, 1 ov. female, 1 pread. male, stn 20, 52°33.763’N 27°20.193’E, 27 m depth.

Campaign 2002: 1 pread. females, 1 juvenile, stn 3, 52°33.464’N 27°30.828’E, 19 m depth; 1 pread. female, stn 10, 52°33.069’N 27°29.796’E, 30 m depth; 1 juvenile, 1 pread. female, 2 ov. females, stn 13, 52°33.831’N 27°29.948’E, 15 m depth; 4 ov. females, stn 14, 52°33.591’N 27°29.677’E, 19 m depth; 5 juveniles, 5 preadult females, 1 ov. female, 1 pread. male, 1 ad. male, stn 15, 52°33.344’N 27°29.421’E, 27 m depth; 1 ov. female, stn 19, 52°34.003’N 27°29.156’E, 19 m depth; 1 juvenile, 3 pread. females, 3 ov. females, stn 24, 52°34.168’N 27°28.797’E, 18 m depth; 1 ad. male without abdomen stn 25, 52°33.921’N 27°28.547’E, 27 m depth.

Diagnosis. Carapace with a dorsal median carina prominent in the anterior half that becomes paired in the hinder half. Anterolateral angle acute and the lower margin smooth. Free thoracic somites with a paired dorsal carina, pereonites 4 and 5 with a faint additional dorsolateral pair. Female antenna proximal article with four plumose setae. Uropod endopod article 1 shorter than article 2.

Description. Ovigerous female, 6.32 mm total length. Carapace near 1/4 of total length ( Fig. 9 A); dorsal median carina prominent in the anterior half becomes paired in the hinder half. Eye­lobe rounded with a pigmented eye; pseudorostral lobes shorts not meeting in front the eye­lobe. Antennal notch deep, anterolateral angle acute and the lower margin smooth. Free thoracic somites with a paired dorsal carina, pereonites 4 and 5 with a faint additional dorsolateral pair.

Antennule ( Fig. 9 B), peduncle triarticulate, article 1 shorter than the following two articles combined length; article 2 and 3 equal length; accessory flagellum uniarticulate, main flagellum biarticulate with two aesthetascs and a long simple seta distally. Antenna ( Fig. 9 B), proximal article with four plumose setae.

Mouthparts: mandible ( Fig. 9 C) with 14 setae between pars incisiva and truncated pars molaris. Maxillule ( Fig. 9 E), palp long, with two unequal filaments. Maxilla ( Fig. 9 F), endites exceeding the protopod, with simple and serrate setae. Maxilliped 1 ( Fig. 9 G), basis with eight plumose setae on inner margin; carpus with eight acuminate setae on inner margin, some simple setae on ventral face and one plumose setae on distal outer corner. Maxilliped 2 ( Fig. 9 H), basis longer than rest of appendage with two long plumose setae distally; carpus longer than propodus and dactylus combined length, with simple and plumose setae on inner margin; propodus broader distally; dactylus shorter than propodus with a long acuminate seta terminally. Maxilliped 3 ( Fig. 10 A), basis produced distally, reaching beyond mero­carpal articulation, inner margin of the projection with long plumose setae; ischium short with four plumose setae on inner margin; merus produced distally with a long plumose seta on the tip of the projection; carpus with the inner margin convex; propodus slightly longer than dactylus.

Pereopods: pereopod 1 ( Fig. 10 B), basis shorter than the rest of appendage, with some setae on the distal half of both margins; ischium shorter than merus; carpus near twice as long as merus and longer than propodus; propodus with a group of long setae on its distal end; dactylus shorter than propodus with two long setae. Pereopod 2 ( Fig. 10 C), basis shorter than rest of appendage, with a rudimentary uniarticulate exopod; ischium very short; merus with a outstanding acuminate seta distally; dactylus longer than merus and carpus, with some rows of acuminate setae, distal seta the longest. Pereopod 3 ( Fig. 10 D), basis longer than the remaining segments together, with a uniarticulate exopod; carpus slightly shorter than merus, with two simple setae on margin and three long simple setae on distal corner; propodus half length of carpus, with one long simple seta on distal corner. Pereopods 4 and 5 similar ( Fig. 10 E, F), basis shorter than rest of appendage, with some simple setae; ischium less than half merus length; carpus slightly shorter than merus, with three simple setae on margin and three long simple setae on distal corner.

Last pleonite not produced between the uropod peduncles, laterally emarginated. Uropod peduncle shorter than rami, with 15 acuminate setae on inner margin; endopod biarticulate, slightly shorter than exopod; article 1 shorter than 2, with ten acuminate setae on inner margin, most distal seta the longest; some plumose setae on outer margin; article 2 with eight microsetulate setae on inner margin and three longer on the tip, outer margin with seven plumose setae.

Male 5.75 mm total length. Carapace about 1/4 of body length ( Fig. 11 A), nearly twice as long as deep, with a dorsal median carina that becomes paired on the hinder half; eyelobe rounded and well pigmented, reaching the tip of pseudorostral lobes; antennal notch shallow, anterolateral angle rounded and smooth.

Antennule ( Fig. 11 B), peduncle triarticulate, article 1 nearly as long as the remaining two, articles 2 and 3 equal in length; accessory flagellum rudimentary, with three setae; main flagellum biarticulate, article 1 twice long as article 2, with some aesthetascs on the proximal half; article 2 with two aesthetascs and two long simple setae.

lateral view; B, antennule; C, pereopod 1; D, pereopod 2; E, uropod.

Pereopods: pereopod 1 ( Fig. 11 C), basis shorter than the rest of appendage with six plumose setae on ventral margin; carpus near twice as long as merus and longer than propodus; propodus longer than dactylus and its terminal setae combined length, with a group of long setae distally. Pereopod 2 ( Fig. 11 D) with a uniarticulate exopod.

Uropod peduncle nearly as long as the rami ( Fig. 11 E); peduncle inner margin with several unequal setae that are more numerous and arranged in different rows in the middle; endopod biarticulate, article 1 as long as article 2, with 12 acuminate setae on inner margin and eight plumose setae on outer margin; article 2 with eight setulate setae on inner margin, seven plumose setae on outer margin and a long microsetulate seta terminally; exopod article 1 shorter than article 2; article 2 with nine long plumose setae on inner margin and four microsetulate setae terminally.

Etymology. From the Latin inermis, meaning unarmed, referring the smooth lower margin of anterolateral angle.

Remarks. Heterocuma inerme sp. nov. resembles very much H. andamani Kurian, 1954 but it differs by the smooth anterolateral margin of carapace, the carpus of first pereopod that is longer than propodus, the number of plumose setae on the antenna of female, and the lower number of setae on the uropod endopod. Moreover, pereonites 2 and 3 have only a paired dorsal carina and lack the prominent dorsolateral and lateral carinae that are characteristic for E. andamani . Both species have the article 1 of endopod shorter than article 2, which differentiate them from H. sarsi Miers, 1879 . This character was misunderstood by Day (1975) in her key of the genus Heterocuma , who mentioned H. sarsi as having uropod endopod article 1 shorter than article 2.

Figures

FIGURE 9. Heterocuma inerme sp. nov., adult female. A, whole animal in lateral view; B, antennule and antenna; C, left mandible; D, labium; E, maxillule; F, maxilla; G, maxilliped 1.

FIGURE 10. Heterocuma inerme sp. nov., adult female. A, maxilliped 3; B, pereopod 1; C, pereopod 2; D, pereopod 3; E, pereopod 4; F, pereopod 5; G, uropod.

FIGURE 11. Heterocuma inerme sp. nov., adult male. A, carapace and pedigerous somites in