Breviturma krohi ( Stöhr, Boissin & Hoareau, 2013 )

Chang, Kai & Shih, Hsi-Te, 2025, Description of a new brittle star of the genus Breviturma (Ophiuroidea: Ophiocomidae), with a new record from Taiwan, European Journal of Taxonomy 997, pp. 28-50 : 40-43

Breviturma krohi ( Stöhr, Boissin & Hoareau, 2013)

Fig. 6

Ophiocoma (Breviturma) krohi Stöhr, Boissin & Hoareau, 2013: 17–20 , figs 2g –l, 4k–o, 5c, f, i, l, o, r, 6.

Ophiocoma sp. nov. – Hoareau et al. 2013: 2.

Ophiocoma (Breviturma) krohi – Boissin et al. 2016: 283 , fig. 3i.

Ophiocoma krohi – Conand et al. 2018: 118 (in list).

Breviturma krohi – Fortaleza et al. 2020: 288, fig. 3b.

Breviturma cf. krohi – Shih et al. 2023: 125 (in list).

non Ophiocoma brevipes Peters, 1851 – Stöhr et al. 2008: 553, figs 5e–f.

Diagnosis

The dorsal disc is densely covered with fine granules that extend seamlessly to the oral side. The oral shields are trapezoidal, while the adoral shields are unevenly triangular. There are four oral papillae and eight to ten tooth papillae. The dorsal arm plates are oval in shape. The arm spines are tapering, with numbers ranging fromthree to five; the proximal arm segments consistently have five spines. The ventral arm plates are pentagonal, each bearing two oval tentacle scales on its lateral sides. The coloration is yellowish-brown, with dark brown patterns on the dorsal disc ( Fig. 6A, C, E–F ). Some of these patterns are pentamerously symmetrical, while others are uniformly dark. The central patterns on the dorsal arm plates are also dark. The arms are transversely banded ( Fig. 6 ), with the arm spines being dark gray. On the oral side, the coloration is light, with tiny dark spots scattered across the surface ( Fig. 6B, D ).

Material examined

TAIWAN – Penghu County • 10 specs (DD = 4.03–12.17 mm); Wang’an, Dongjiyu ; 23°15′24.9″ N, 119°39′59.4″ E; depth <1 m; 22 Apr. 2024; K. Chang and Y.-C. Hsu leg.; NCHUZOOL 17274 • 1 spec. (DD = 8.68 mm); Wang’an, Dongjiyu ; 23°15′24.9″ N, 119°39′59.4″ E; depth <1 m; 24 Apr. 2024; K. Chang and Y.-C. Hsu leg.; NCHUZOOL 17275 • 5 specs (DD = 7.67–12.13 mm); Wang’an, Dongjiyu ; 23°15′24.9″ N, 119°39′59.4″ E; depth <1 m; 25 Apr. 2024; K. Chang and Y.-C. Hsu leg.; NCHUZOOL 17276 • 2 specs (DD = 10.90–11.01 mm); Wang’an, Dongyupingyu ; 23°15′29.1″ N, 119°30′46.5″ E; depth 1 m; 28 Apr. 2024; K. Chang and Y.-C. Hsu leg.; NCHUZOOL 17277 . – Pingtung County • 2 specs (DD = 6.05–9.36 mm); Siaoliouciou, Shanfu Fishery Harbor ; 22°20′24.4″ N, 120°21′46.2″ E; depth <1 m; 12 Feb.2023; K. Chang and Y.-C. Hsu leg.; NCHUZOOL 17258 • 1 spec. (DD = 10.99 mm); Checheng, Huangjin Beach ; 22°04′52.6″ N, 120°42′06.2″ E; depth <1 m; 25 Feb. 2024; K. Chang et al. leg.; NCHUZOOL 17270 • 3 specs (DD = 7.27–9.12 mm); Hengchun, Houbihu ; 21°56′18.9″ N, 120°44′43.6″ E; depth <1 m; 25 Dec. 2023; K. Chang et al. leg.; NCHUZOOL 17269 • 2 specs (DD = 10.46–12.06 mm); Hengchun, Wanlitong ; 21°59′44.4″ N 120°42′22.2″ E; depth <1 m; 26 Feb. 2024; K. Chang et al. leg.; NCHUZOOL 17271 • 6 specs (DD = 3.95–12.73 mm); Hengchun, Wanlitong ; 21°59′42.4″ N, 120°42′22.3″ E; depth 5 m; 28 Feb. 2024; K. Chang et al. leg.; NCHUZOOL 17273 • 1 spec. (DD = 12.27 mm); Mudan, Gangzaibi ; 22°08′49.8″ N, 120°53′32.4″ E; depth <1 m; 27 Feb. 2024; K. Chang et al. leg.; NCHUZOOL 17272 . – Taitung County • 2 specs (DD = 6.21–9.43 mm); Chenggong, Jihuei ; 23°07′00.4″ N, 121°23′50.1″ E; depth <1 m; 11 Apr. 2023; K. Chang et al. leg.; NCHUZOOL 17260 • 6 specs (DD = 6.81–11.73 mm); Donghe, Dulan ; 22°51′51.7″ N, 121°12′34.9″ E; depth <1 m; 16 Oct. 2024; K. Chang et al. leg.; NCHUZOOL 17337 • 1 spec. (DD = 6.20 mm); Lanyu, Dongcing ; 22°04′29.2″ N, 121°34′04.3″ E; depth <1 m; 15 Mar.2023; K. Chang et al. leg.; NCHUZOOL 17259 • 4 specs (DD = 9.00– 12.99 mm); Lanyu, Longmen Harbor ; 22°00′16.5″ N, 121°34′52.7″ E; depth 7 m; 23 May 2023; C.-H. Chang et al. leg.; NCHUZOOL 17261 • 3 specs (DD = 9.44–12.07 mm); Lanyu, Longmen Harbor ; 22°00′16.5″ N, 121°34′52.7″ E; depth 7 m; 24 May 2023; K. Chang and Y.-C. Hsu leg.; NCHUZOOL 17262 • 1 spec. (DD = 17.17 mm); Lanyu, Langdao ; 22°04′45.3″ N, 121°31′47.9″ E; depth <1 m; 25 May 2023; K. Chang and Y.-C. Hsu leg.; NCHUZOOL 17263 • 1 spec. (DD = 13.57 mm); Lanyu, Langdao ; 22°04′45.3″ N, 121°31′47.9″ E; depth <1 m; 6 Jul. 2023; K. Chang and Y.-C. Hsu leg.; NCHUZOOL 17264 • 1 spec. (DD = 11.36 mm); Lanyu, Dongcing ; 22°03′23.1″ N, 121°33′56.8″ E; depth <1 m; 6 Jul. 2023; K. Chang et al. leg.; NCHUZOOL 17265 • 8 specs (DD = 4.94–13.23 mm); Lanyu , “ Jimavonot ” [ Jade Maiden Rock ]; 22°04′53.6″ N, 121°31′05.7″ E; depth 8 m; 7 Jul. 2023; K. Chang and Y.-C. Hsu leg.; NCHUZOOL 17266 • 1 spec. (DD = 15.58 mm); Lanyu, Langdao ; 22°04′45.3″ N, 121°31′47.9″ E; depth <1 m; 15 Sep. 2023; K. Chang and Y.-C. Hsu leg.; NCHUZOOL 17267 • 1 spec. (DD = 8.45 mm); Lanyu, Hongtou ; 22°01′19.4″ N, 121°33′29.7″ E; depth <1 m; 15 Sep. 15; K. Chang et al. leg.; NCHUZOOL 17268 .

Ecological and behavioral notes

This species inhabits sandy substrates beneath rocks, ranging from the intertidal zone to shallow subtidal zone. In Taiwan, it is highly sympatric with other brittle stars, including B. dentata , B. securis sp. nov., Ophiocoma scolopendrina , and Amphipholis squamata .

Distribution

Indo-West Pacific: Reunion Island; Okinawa Islands, Japan; Taiwan; Philippines; Palau; Mariana Islands; Wake Island; Samoa; Niue; Hawaii; Society Islands, Polynesia.

Remarks

Breviturma krohi with uniformly dark color pattern sometimes can be confused with B. dentata in appearance. While these two species can be separated using 1) the arm spine numbers from proximal arm segments, which are four or five ( Stöhr et al. 2013; our material) (vs four in B. dentata ); 2) the W/ L ratios of dorsal arm plates, which are lower in B. krohi (ca 1.8) ( Stöhr et al. 2013) (vs 2.0 in B. dentata ); and 3) the maximum disc diameter of this species, which is 17.17 mm in our material (vs 28 mm in B. dentata ).

Figures

Fig. 6. Breviturma krohi (Stöhr, Boissin & Hoareau, 2013). A–B. Ethanol preserved specimen (NCHUZOOL 17274), DD = 11.40 mm. C–D. Ethanol preserved specimen (NCHUZOOL 17266), DD = 4.94 mm. E–H. B. krohi, in situ. Scale bars: A–B = 30 mm; C–D = 10 mm.