Atarbolana exoconta Bruce & Javed, 1987

Khalaji-Pirbalouty, Valiallah & Raupah, Michael J., 2016, DNA barcoding and morphological studies confirm the occurrence of three Atarbolana (Crustacea: Isopoda: Cirolanidae) species along the coastal zone of the Persian Gulf and Gulf of Oman, Zootaxa 4200 (1), pp. 153-173 : 155-162

publication ID	https://doi.org/ 10.11646/zootaxa.4200.1.7
publication LSID	lsid:zoobank.org:pub:202F2722-B0DF-44E3-9F0D-CD809148B8B5
DOI	https://doi.org/10.5281/zenodo.5624457
persistent identifier	https://treatment.plazi.org/id/03BC87AE-FF81-FFEA-EBEC-F97F979F2719
treatment provided by	Plazi
scientific name	Atarbolana exoconta Bruce & Javed, 1987
status

Treatment

Atarbolana exoconta Bruce & Javed, 1987 View in CoL

( Figs 2–6 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 View FIGURE 6 )

Atarbolana exoconta Bruce & Javed, 1987: 145 View in CoL , figs. 1–2.

Type material. Holotype: ♂, AM P37199. Paratypes: 1 ♀, 1 ♂, slide, AM. P.37200 (examined). Type locality: Manora Island, Karachi , Pakistan, 24°47'40"N, 66°58'39"E. GoogleMaps

Diagnosis. Body about 2.5 times as long as greatest width; antennal peduncle article 3 with 3–4 very long simple setae on ventral margin, flagellar articles in male lacking a tuft of long setae; Pleotelson abruptly narrowed distally, apex rounded with 10–16 marginal RS; uropodal endopod not reaching to pleotelson apex, exopod extended well beyond pleotelsonic apex, peduncle ventromedial surface with a row of 9 RS; appendix masculina arising above mid-point of endopod medial margin, extending slightly beyond endopod distal margin and tapering to an acute apex.

Material examined. 1 ♂ (4.6 mm); 3 ♀ (5, 4.3, 4.1 mm), Gatan-Paein , Hormuzgan Province, Iran, Gulf of Oman, rocky intertidal shore covered with algae, 25°58'01.03"N, 57°15'13.63"E, 30 June 2013, coll. Khalaji- Pirbalouty ( ZMSU 1010 View Materials ) GoogleMaps . 3 ♂ (7.2, 7, 5 mm); 5 ♀ (7.1, 6.8, 5.9, 5.4, 5), Hengam Island, Persian Gulf , 26°37'17.63"N, 55°52'49.99"E, 20 February 2014, coll. Khalaji-Pirbalouty ( ZMSU 1011 View Materials ) GoogleMaps . 1 ♂ (7.2 mm); 1♀ (7 mm), Mina Abdullah, Persian Gulf , Kuwait, 29°00'10.20"N, 48°09'09.55"E, 10 February 2014 ( ZMSU 1012 View Materials ) GoogleMaps . 1 ♂ (5.4 mm); 1 ♀ (4.5 mm), Masfat Al-Ahmadi, Persian Gulf , Kuwait, 29°04'05.80"N, 48°08'07.35"E, 10 December 2014, ( ZMSU 1013 View Materials ) GoogleMaps .

Description of male (from Gatane Paein, Gulf of Oman, Iran). Body 2.4 times as long as greatest width, widest at pereonite 5 ( Fig. 2 View FIGURE 2 A). Head with minute rostral process, with 2 posterior sutures. Pereonites 4–7 bearing scattered small tubercles; pereonites 2–3 with sub-quadrate coxal plates; coxal plates 5–7 progressively more produced and acute posteriorly, all coxal plate ventral margins fringed with long simple setae ( Fig. 2 View FIGURE 2 B).

Pleon ( Fig. 2 View FIGURE 2 A) with pleonites 3–5 with scattered small tubercles; pleonite 3 visible dorsally; pleonite 4 extended well over lateral margins of pleonite 5 and proximal part of pleotelson.

Pleotelson ( Fig. 2 View FIGURE 2 A) with 2 bimedian depressions, dorsal surface with 4 long simple setae medially and scattered small tubercles; posterior margin bearing 10 marginal RS set between long PMS ( Fig. 2 View FIGURE 2 C, D, E).

Antennula ( Fig. 2 View FIGURE 2 F) extending to posterior margin of pereonite 3, peduncle article 3 approximately 1.6 times as long as article 2; flagellum with 16 articles, articles 7–16 bearing 1 or 2 aesthetascs.

Antenna ( Fig. 2 View FIGURE 2 G) peduncle articles 1 and 2 short, articles 3 and 4 longer and subequal in length; all peduncle articles each with a group of long simple setae on anterodistal corner, article 3 with 4 very long simple setae on ventral margin; flagellum with 18 articles, extending to posterior margin of pereonite 2.

Left mandible ( Fig. 3 View FIGURE 3 A, B) molar process anterior margin with about 27 flat teeth; spine row composed of 10 spines; palp article 2 longest with 10 robust biserrate setae, and 2 long submarginal RS; article 3 with 10 robust biserrate marginal setae.

Maxillula ( Fig. 3 View FIGURE 3 C) lateral endite with 9 RS (weakly serrated); mesial endite with 3 large circumplumose RS and 2 short simple setae.

Maxilla ( Fig. 3 View FIGURE 3 D) lateral and middle endites with 4 and 5 long finely plumose setae respectively; mesial endite with 5 long circumplumose RS and 4 simple RS.

Maxilliped palp ( Fig. 3 View FIGURE 3 E) article 1 with 7 distally placed long setae, articles 2–5 lateral margins with 2, 8, 3 and 6 slender simple setae respectively; articles 3– 5 with continuous fringe of finely biserrate setae on medial margin; endite ( Fig. 4 View FIGURE 4 F) with 4 long CPS, and 3 coupling hooks.

Pereopod 1 ( Fig. 4 View FIGURE 4 A) basis 3.2 times as long as wide, superior margin with 2 long simple and 1 SPS, posterodistal corner with 3 long finely plumose setae; ischium inferior margin with 2 long simple setae, mediodistal margin with 4 long simple setae, superodistal corner with 4 long setae; merus inferior margin with 3 RS and 2 long simple setae, mediodistal margin with 1 long simple setae, superiodistal corner with 3 long simple setae; carpus inferior margin with 2 RS and 4 long simple setae; propodus inferior margin with 9 RS, superior margin with 1 simple setae, superodistal corner with 2 simple setae; dactylus with minute secondary unguis.

Pereopod 2 ( Fig. 4 View FIGURE 4 B) basis 2.6 times as long as wide, superior margin with 7 long simple and 2 SPS, posterodistal corner with 5 long finely plumose or simple setae; ischium inferior margin with 5 long simple setae, mediodistal margin with 5 long simple setae, superiodistal corner with 2 long simple setae and 1 long RS; merus inferior margin with 4 RS and 4 long simple setae, mediodistal margin with 3 long simple setae, superodistal corner with 4 long simple setae and 1 RS; carpus inferior margin with 4 RS; propodus inferior margin with 6 RS, superodistal corner with a SPS and 2 simple setae; dactylus with minute secondary unguis.

Pereopod 3 ( Fig. 4 View FIGURE 4 C) similar to pereopod 2.

Pereopod 4 ( Fig. 4 View FIGURE 4 D) basis 2.3 times as long as wide, with 3 long simple marginal and 2 SPS, posterodistal corner with 6 long simple or finely biserrate setae; ischium inferomedial surface with 4 RS, inferodistal corner with 3 long simple and 3 RS, mediodistal margin with 3 long simple setae, superodistal corner with 4 RS; merus inferodistal corner with 5 long simple RS and 1 serrate RS, superodistal corner with 4 long simple RS and 1 serrate RS; carpus inferodistal corner with 4 simple RS and 1 serrated RS, superodistal corner with 2 RS; propodus inferior margin with 3 RS; dactylus with minute secondary unguis.

Pereopod 5 ( Fig. 5 View FIGURE 5 A) and Pereopod 6 ( Fig. 5 View FIGURE 5 B) are similar to pereopod 4 as illustrated.

Pereopod 7 ( Fig. 5 View FIGURE 5 C) basis 2.8 times as long as wide; ischium inferior margin with 3 sets of long simple and robust setae, superodistal corner with 4 simple and 3 biserrated RS; merus and carpus superior and inferior margins fringed with numerous long plumose setae; propodus inferior margin with 2 sets of RS, superodistal corner with 1 RS, 1 simple and 1 SPS; dactylus with minute secondary unguis.

Pleopod 1 ( Fig. 6 View FIGURE 6 A) exopod and endopod with ~40 and 19 PMS, endopod as long as exopod; sympod mesial margin with 4 coupling hooks and 1 plumose seta, lateral margin with a single RS.

Pleopod 2 ( Fig. 6 View FIGURE 6 B) exopod and endopod with ~41 and 12 PMS respectively; appendix masculina arising above 0.59 of endopod medial margin, extending slightly beyond endopod distal margin (by approximately 0.2 times of length), tapering to an acute apex; sympod mesial margin with 3 coupling hooks and 2 plumose setae, lateral margin with a single sub-marginal RS.

Pleopod 3 ( Fig. 6 View FIGURE 6 C) and Pleopod 4 ( Fig. 6 View FIGURE 6 D) essentially similar, exopod with ~48 and ~42 PMS, and partial transverse suture; sympod medial margin with 3 coupling hooks and 2 plumose setae, lateral margin with single sub-marginal RS.

Pleopod 5 ( Fig. 6 View FIGURE 6 E) exopod with 45 PMS, and partial transverse suture; sympod without coupling hook, lateral margin with single plumose sub-marginal RS.

Penes ( Fig. 6 View FIGURE 6 F) short, separate but adjacent, 2.8 times as long as basal width.

Uropod ( Fig. 5 View FIGURE 5 D); endopod not reaching to pleotelsonic apex, with 18 marginal RS; exopod ( Fig. 5 View FIGURE 5 E) elongate, slender, nearly 1.7 times as long as endopod, extended well beyond pleotelsonic apex, dorsolateral margin with 2 RS, ventromedial margin with 5 RS, distal margin with a tuft of long simple setae, 1 prominent RS and 1 small RS; peduncle ventromedial surface with a row of 9 RS.

Female. Apart from sexual characters, uropod rami are smaller than in male and extending just beyond the pleotelsonic apex, endopod with 18 marginal RS, exopod dorsolateral margin with 2 RS, ventro-medial margin with 4 RS; pleotelson with 8 marginal RS, elongation less than in male.

Variations. Pleotelson marginal RS (n = 28 [12 ♂ and 16 ♀]) males with 10–16 RS, with 16 RS (33.3%) most frequent, 12 (25%), 10 (13.8%), 13 (13.8%), and 14 (8.3 %) occurring only once; in females with 8–14 RS, with 10 RS (43.7 %) most frequent, with 8 (18.7 %), 12 (18.7 %), 14 (18.7 %). Uropod endopod in males with 18–22 RS, with 18 RS (58%) most frequent, with 20 (33%), and 22 (8.3 %) occurring only once; in females 18–20 RS, with 18 (81%) most frequent, and 20 (19%).

Remarks. Atarbolana exoconta Bruce & Javed, 1987 can be identified by the antennal flagellum lacking long setae and peduncle article 3 with 4 very long simple setae on ventral margin; pleopod 2 endopod with appendix masculina extending slightly beyond endopod distal margin. The ventral surface of the uropod peduncle with a row of 9 RS. In comparison of the new specimens from the Persian Gulf and Gulf of Oman with type material, no morphological differences could be found. However, some variations are seen within the specimens of different populations, these variations are seen in number of the pleotelson marginal RS (10 –16 RS) and number of the uropodal endopod marginal RS (18 –22 RS).

Distribution. Manora Island, Karachi, Pakistan; Gulf of Oman (Hormuzgan Province, Iran); Persian Gulf ( Qeshm Island, Kuwait).