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| Speolabeo hokhanhi
Tao, Cao, Deng & Zhang, 2018
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Abstract
Speolabeo hokhanhi, new species, is here described from Hang Va Cave in Phong Nha-Ke Bang National Park (Son River basin) in Central Vietnam. It can be distinguished from S. musaei by having no papillae on the lower lip, no hump immediately behind the head, a duckbilled snout, a shorter caudal peduncle (length 16.8–18.6% SL), and the pelvic fin inserted closer to the snout tip than to the caudal-fin base.
Keywords: Pisces, Speolabeo, new species, cavefish, Central Vietnam
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| FIGURE 2. Speolabeo hokhanhi sp. nov., fresh individual immediately after capture. Lateral view. |
Speolabeo hokhanhi sp. nov.
Diagnosis. Speolabeo hokhanhi can be easily distinguished from S. musaei by having a lower lip without papillae (vs. with a band of papillae along its anterior margin), no hump immediately behind the head (vs. present), a duckbilled (vs. pyramidal) snout, the pelvic fin inserted closer to the snout tip than to the caudal-fin base (vs. midway between the snout tip and caudal-fin base) and a shorter (vs. longer) caudal peduncle (length 16.8–18.6% SL vs. 19.6–22.7). All data here used for S. musaei are from Kottelat and Steiner (2011).
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Etymology. The specific epithet is named in honor of Mr. Ho Khanh who discovered many caves in Phong Nha–Ke Bang National Park. He was a local guide of the cavefish survey conducted by the first author during 2014 into the cave where the type specimens were collected and provided detailed information about the collection site.
As common names, we suggest Hokhanh’s Blind-cavefish (English)
and cá mù hang va hồ-khanh (Vietnamese).
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| FIGURE 4. Distribution of Speolabeo hokhanhi (▲). |
Distribution and habitat. Speolabeo hokhanhi is known only from the type locality (Fig. 4). Hang Va Cave is
roughly 35 km south of Phong Nha village, rather close to Hang Son Doong, the world’s largest known cave that is
5 km long, 200 m high and 150 m wide. A 24 km southward drive along the West Ho–Chi–Minh highway starting
from the tourism center of the Phong Nha–Ke Bang National Park leads to the point closest to the cave site of the
Hang Son Doong. From there, roughly 1.5 hours’ northward walk following a narrow stony track through thick
forest arrives at Hang Va Cave. Its entrance is about 30 meters above the ground. A descent of 15 m from the
entrance reaches a cave passage containing a subterraneous stream. Downstream for approximately 200 meters,
there is a shallow water pool with many stalagmites, usually 2–3 m tall (Fig. 5), where the type specimens of the
new species were collected during the dry season. At this time, the pool had a muddy substrate and was 0.5–1.5 m
in depth, 10 m wide, and 25 m long. More than 30 individuals of about the same size were observed in the pool;
only six were captured using a hand-net. The fishes were swimming slowly and haphazardly, rather close to the
water surface; when disturbed, they swam deeper, but did not seek shelter. A new shrimp species was found to
sympatrically occur with the cavefish (Do & Nguyen 2014).
Nguyen Dinh Tao, Liang Cao, Shuqing Deng and E Zhang. 2018. Speolabeo hokhanhi, A New Cavefish from Central Vietnam (Teleostei: Cyprinidae). Zootaxa. 4476(1); 109–117. DOI: 10.11646/zootaxa.4476.1.10
