Cirolana andamanensis Rodcharoen, Bruce & Pholpunthin, 2016

Bruce, Niel L., 2017, Review of the species of the Cirolana ‘ parva - group’ (Cirolanidae: Isopoda: Crustacea) in Indonesian and Singaporean waters, Zootaxa 4317 (3), pp. 401-435 : 404

Cirolana andamanensis Rodcharoen, Bruce & Pholpunthin, 2016

Cirolana andamanensis RodCharoen, BruCe & Pholpunthin, 2016: 1940 –1949, figs 2–6.

Type and type locality. The holotype is deposited at PSUZC; type locality is Nai Yang Beach , Phuket Province, Thailand, 08°05'07"N, 98°17'06"E ( PSUZC –CR0282-01).

Material examined. Indonesia series. 8 ♂ (3.7, 4.4, 4.4, 4.6 [dissected], 5.0, 5.1, 5.2, 6.2 mm), 4 ♀ (3.0, 3.0, 5.0, 5.0 mm), 1 manca (2.2 mm), Teluk Medana, Lombok, 8°21'34.00''S, 116°07'25.59''E, 14 August 2014, diving 6 m, rubble and dead coral head, coll. C.M. Sidabalok and party ( MZB Cru.Iso 047) . 3 ♂ (4.5, 4.5, 4.5 mm), 3 ♀ (3.9, 4.0, 4.4 mm), Teluk Medana, Lombok, 8°21'34.00''S, 116°07'25.59''E, 14 August 2014, diving 6 m, rubble and dead coral head, coll. C.M. Sidabalok and party (MTQ W52891). 3 ♂ (4.0, 4.4, 5.0 mm), 1 ♀ (4.5 mm), Gili Trawangan, Lombok, 8°21'3.629''S, 116°01'37.74''E, 9 August 2014, diving 8 m, rubble and dead coral head, coll. C.M. Sidabalok and party (MZB Cru.Iso 048). 2 ♂ (5.0, 5.7 mm), 1 ♀ (4.9 mm, ovigerous), Gili Air, Lombok, 8°21'27.238''S, 116°05'17.206''E, 13 August 2014, diving 10 m, rubble and dead coral head, coll. C.M. Sidabalok and party (MZB Cru.Iso 049). 3 ♂ (5.5, 6.8, 6.9 mm), Teluk Kodek, Lombok, 8°24'13.44''S, 116°04'19.02''E, 11 August 2014, hand collection on intertidal reef, coll. C.M. Sidabalok and party (MZB Cru.Iso 050).

Singapore series. 1 ♂ (8.0 mm), Sisters Island , 01°12.789'N, 103°50.187'E, 26 May 2015, intertidal reef, rocky reef, coll. Lee Yen Ling and party, IT81 SS1931 ( ZRC 2017.0756 ).

Variation. Cirolana andamanensis specimens from Lombok are smaller in size than the specimens from Thailand and Singapore (male average size 5.4 vs 6.6 mm).

Remarks. The distinguishing characters of Cirolana andamanensis are the fused articles 1 and 2 of the antennula peduncle, absence of a setal fringe on male pereopod 1, low tubercular penes separated by 3% of the sternal width, and the weakly concave lateral margin of pleopod 1 (Rodcharoen et al. 2016).

Within the Indo-Malaya region Cirolana andamanensis is most similar to C. improceros Bruce, 1986 having in common close-spaced penial openings and concave lateral margin of the endopod of pleopod 1. Cirolana improceros differs in having a slightly longer (1.5 vs 1.4) and distally recurved (vs straight) appendix masculina.

The specimens of Cirolana andamanensis from Lombok are consistently smaller than those from the Andaman Sea coast of Thailand, by about 18–22%, averaging 5.4 mm in Lombok vs 6.6 mm in Thailand. This suggests that the two populations may be distinct, but we were not able to identify any morphological differences and were unable to obtain molecular data to further assess the genetic differences.

Distribution. Extended from the previous record in the Andaman Sea, Thailand (Rodcharoen et al. 2016) to the new records in Singapore and Indonesia (Lombok) ( Fig. 1 ).

Figures

FIGURE 1. Distribution map of Cirolana ‘ parva group’ in Indo-Australian region (C – H, Indonesia; I, PNG; J – K, Australia). LoCation symbols: A = Thailand, B = Singapore, C = Lombok, D = Bitung, E = Pulau Pombo, Maluku, F = Raja Ampat, G = Kei Islands, H = Kaimana, I = Madang, J = Lizard Island, K = HinChinbrook Island. SpeCies symbols: Cirolana andamanensis (-), Cirolana arafurae (×), Cirolana improceros (v), Cirolana leptanga (O), Cirolana siamensis (O), Cirolana stenoura (A), Cirolana thailandica (Ł), Cirolana molari (Ɨ), Cirolana peisanae (+), Cirolana duo (Ŧ).