Karstama boholano
Creators: name: Li, Jheng-Jhang
name: Shih, Yi-Jia
name: Ho, Ping-Ho
name: Jiang, Guo-Chen
Publisher: name: Zenodo
Year: 2019
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Sesarmidae
Karstama
Karstama boholano

description: Karstama boholano (Ng, 2002)
Sesarmoides boholano Ng 2002: 428, figs. 11, 12, 15A, B, 16B, 17b; Naruse et al. 2005: 80.
Karstama boholano Ng et al. 2008: 221; Fujita and Naruse 2016: 23.
Material examined: 1 female (19.3 × 15.6) (DNA voucher, NTOU 1), eastern Green Island, 17 September 2017, C.-Y. Lu; 1 female (20.3 × 16.3) (DNA voucher, NTOU 2), western Green Island, 18 September 2014, J. J. Li; 1 female (19.2 × 15.2) (NTOU 3), Siaobalidao, KTNP, 20 August 2018, J.-J. Li.
Additional material: Karstama boholano (Ng, 2002). — Paratypes: 2 males (14.0 × 12.0, 11.3 by 9.8 mm), 2 females (10.5 by 8.8 mm, 10.4 by 9.2 mm) (largest female as DNA voucher, TMCD), Panglao Island, Bohol, Philippines, coll. H.-C. Liu, 26 Nov. 2001; 1 female (18.1 × 14.9) (DNA voucher, ZRC 2012.0433-1), 1 male (17.2 × 14.6) (DNA voucher, ZRC 2012.0433-2) Philippines: Bohol, Central Panglao, Panglao Nature Resort grounds, Karst Forest, inside cave, Dec. 2010, P. K. L. Ng and P. Y. C. Ng.
Comparative material: Sesarmoides kraussi (De Man, 1887). — (24.1 × 18.5) (DNA voucher, NTOU 0), Ryukyu Island, Japan, 18 July 2016, J. J. Li.
Diagnosis: Detailed diagnoses of adults were provided by Ng (2002) (specimens from Philippines), Naruse et al. (2005), and Fujita and Naruse (2016) (specimens from Japan). The females from Taiwan generally corresponded to the above description.
Description of the first zoeal stage: Size: CL, mean 0.35 mm (range 0.30-0.40 mm; n = 10)
Carapace (Fig. 1A): Lateral spine absent; dorsal spine present, without tubercles, relatively short and curved; rostral spine present, without tubercles, approximately same length as dorsal spine; rostral spine shorter than antennal protopod, without distal spinulation; 1 pair of anterodorsal and posterodorsal setae; ventral margin smooth and without setae; eyes sessile.
Antennule (Fig. 1B): Uniramous, endopod absent; exopod unsegmented with 3 (2 broad and 1 slender) terminal asethetascs and 2 terminal setae.
Antenna (Fig. 1C): Protopod longer than antennule and bearing two rows of small lateral spines; endopod absent; exopod elongated, approximately 1/3 of protopod length and with 1 long, 1 short terminal setae and 3 small terminal spines.
Mandible (Fig. 1D): Endopod palp absent.
Maxillule (Fig. 1E): Epipod seta absent; coxal endite with 6 plumose setae; basial endite with 5 setal processes; endopod 2-segmented, proximal segment with 1 seta, distal segment with 1 subterminal seta and 4 terminal setae; exopod seta absent.
Maxilla (Fig. 1 F): Coxal endite bilobed, proximal lobe with 5 setae, distal lobe with 3 setae + 1 rudimentary seta; basial endite bilobed with 5 (1 short simple seta + 4 plumose setae) + 4 plumose setae; endopod with 2 + 3 terminal setae; scaphognathite margin with 4 setae and 1 long stout plumose distal process.
First maxilliped (Fig. 1G): Coxa with 1 seta; basis with 10 setae arranged as 2, 2, 3, 3; endopod 5-segmented with 2, 2, 1, 2, 5 (1 subterminal + 4 terminal) setae, and with a cluster long fine setae on the outer side; exopod unsegmented, distal segment with 4 long terminal plumose natatory setae.
Second maxilliped (Fig. 1H): Coxa without setae; basis with 4 setae arranged as 1, 1, 1, 1; endopod 3-segmented with 0, 1, 6 (3 subterminal + 3 terminal) setae; exopod unsegmented, distal segment with 4 long terminal plumose natatory setae.
Third maxilliped: Absent.
Pereiopods: Absent.
Abdomen (Fig. 1I, J): With 5 somites; somites 2-3 with pair of dorsolateral processes; somites 1-2 with short posterolateral spinous processes, somites 3-5 with subacute posterolateral spinous processes; somites 2-5 with 1 pair of posterodorsal setae; pleopods absent.
Telson (Fig. 1 I-K): Telson bifid, curved upward distally; with 1 pair of minute lateral spines; generally spinulated on each furca; posterior margin with 3 pairs of stout spinulate spines.
Distribution: Karstama boholano has been reported from both northern and southern Taiwan; and Panglao Island, Bohol, Philippines (type locality); Ishigaki Island and Tarama-jima Island, Ryukyu Islands; and southwestern Japan (Ng 2002; Naruse et al. 2005; Fujita and Naruse 2016). As such, the discovery of this species in Taiwan was predicted and is finally confirmed here.
Ecological notes: Two ovigerous female specimens of Karstama boholano were collected together with ovigerous Metasesarma aubryi (A. Milne Edwards, 1869) during their breeding migration. Metasesarma aubryi is a common crab species from Taiwan and adjacent areas, ovigerous females of the species usually release their larvae during the last quarter of the lunar month from July to September (unpublished data). The first female K. boholano (Fig. 2A, B) was found at approximately 03:30 on September 18, 2014, walking under a streetlight. The first author immediately took the crab to the intertidal zone and allowed it to release its free-swimming zoeae into the sea (the zoeae were not collected). The second female (Fig. 2C, D) was found at 20:00 on September 17, 2017. A Green Island resident collected the ovigerous female in a container filled with seawater, and the free-living zoeae were released between 03:00 and 05:00. We believe that the larval release time and rhythm follow a lunar rhythm, peaking in September. A third female (Fig. 2E) was collected from the corrosion cleft on the limestone located in the coastal forest of KTNP, which the literature (Ng 2002; Naruse et al. 2005; Fujita and Naruse 2016) suggests is not a typical cavernicolous environment (Fig. 2F).
Remarks: Fujita and Naruse (2016: 26, Fig. 3) provide a clear description of female vulvae morphology based on Japanese material, which is a diagnostic character that can be compared to the Taiwanese material. The material in both areas had the same characters: the vulvae’s central operculum protruded in a cone shape and there was no raised sternal vulvar cover (Fig. 3A, B). On the other congener species, the central operculum was mostly rounded (Wowor and Ng 2009). In addition, our data revealed that the female K. boholano from Taiwan has a larger body (average cw. 19.6 mm, n = 3) than specimens from Panglao (average cw. 13.0 mm, n = 6) and Okinawa (average cw. 16.7 mm, n = 3) (measurements of females from Ng 2002; Naruse et al. 2005; Fujita and Naruse 2016).
Molecular analyses: Karstama boholano had belonged to the genus Sesarmoides; therefore, S. kruasii was chosen as the outgroup in this study. The result revealed that all the specimens collected from Green Island or the Philippines emerged from the same branch of K. boholano. Moreover, the intra-specific threshold was around 0 to 0.5% divergence of K2P distances, and the threshold between the two genera was shown to be 41.3% in this study (Table 2).
description: Published as part of Li, Jheng-Jhang, Shih, Yi-Jia, Ho, Ping-Ho & Jiang, Guo-Chen, 2019, Pampus candidus, pp. 1-9 in Zoological Studies 58 (36) on pages 2-6, DOI: 10.6620/ZS.2019.58-36, http://zenodo.org/record/12821446