Research Article |
Corresponding author: Seung-woon Yun ( ysw0314@jbnu.ac.kr ) Corresponding author: Jong-young Park ( park7877@jbnu.ac.kr ) Academic editor: Yahui Zhao
© 2023 Su-hwan Kim, Seung-woon Yun, Jong-young Park.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Kim S-h, Yun S-w, Park J-y (2023) A new species of torrent catfish, Liobagrus geumgangensis (Teleostei, Siluriformes, Amblycipitidae), from Korea. ZooKeys 1180: 317-332. https://doi.org/10.3897/zookeys.1180.105233
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In a recent survey of populations of the Korean torrent catfish Liobagrus, a distinctive species was discovered from the Geum River and its tributaries flowing into the western coast of Korea, and here described as a new species, L. geumgangensis sp. nov. It is distinguishable from other congeners by a combination of the following characters: I, 8 pectoral fin-rays; 52–56 caudal-fin rays; a relatively short occiput to dorsal-fin origin distance (6.9–9.8% SL); a short pelvic-fin insertion to anal-fin origin distance (11.9–17.3% SL); a long dorsal-fin base (10.6–13.5% SL); 8–9 gill rakers; 5–8 serrations on the pectoral fin; the body and fins are dark yellow, the margins of the dorsal, anal, and caudal fins are dark brown, but the outermost rim is faintly yellow. Analysis of the cytb gene also confirmed that L. geumgangensis is a monophyletic lineage distinct from other congeners.
Catfishes, cytb, DNA, geographical speciation, key, morphometrics, taxonomy
The family Amblycipitidae, which includes four genera (Liobagrus Hilgendorf, 1878; Amblyceps Blyth, 1858; Xiurenbagrus Chen & Lundberg, 1995; Nahangbagrus Nguyen & Vo in
Genus Liobagrus can be distinguished from the genus Amblyceps by its pale fin margins, adipose fin confluence with the caudal fins, rounded or truncated caudal fin (
The Korean Peninsula is largely divided into western and eastern halves by the Baekdudaegan Mountain Range. Recent studies on freshwater fish from Korea have focused on taxonomic reviews of fish separated by this range: Koreocobitis rotundicaudata (West),
All samples were collected using a scoop net, fixed in 10% formalin, and preserved in 80% ethanol. Count and measurement procedures were taken following
Morphometrics | Holotype | Paratype (N = 20) | ||
---|---|---|---|---|
range | mean | SD | ||
Standard length (mm) | 70.7 | 57.0–88.3 | 73.8 | 9.3 |
In percentages of standard length | ||||
Preocciput length | 23.0 | 19.8–24.2 | 21.8 | 1.2 |
Predorsal length | 30.7 | 27.3–31.5 | 30.1 | 1.1 |
Prepectoral length | 21.5 | 18.8–23.4 | 21.6 | 1.1 |
Prepelvic length | 44.7 | 42.7–47.4 | 45.6 | 1.4 |
Distance from occiput to dorsal-fin origin | 9.1 | 6.9–9.8 | 8.0 | 0.7 |
Distance from pectoral-fin origin to dorsal-fin origin | 14.7 | 14.0–16.0 | 15.0 | 0.6 |
Distance from pectoral-fin origin to pelvic-fin origin | 24.6 | 23.3–30.3 | 27.1 | 1.7 |
Distance from dorsal-fin origin to pelvic- fin origin | 22.9 | 21.6–28.1 | 25.1 | 1.7 |
Distance from pelvic-fin origin to adipose- fin origin | 16.5 | 14.8–21.6 | 18.0 | 1.4 |
Distance from pelvic-fin origin to anal-fin origin | 14.8 | 11.9–17.3 | 14.5 | 1.4 |
Anal-fin base length | 18.3 | 16.4–20.4 | 18.8 | 1.0 |
Dorsal-fin base length | 12.1 | 10.6–13.5 | 11.8 | 0.8 |
Occiput to pectoral-fin origin | 12.5 | 10.9–14.3 | 12.5 | 1.0 |
Interorbital width | 8.6 | 6.2–8.5 | 7.4 | 0.6 |
Body width at pectoral-fin origin | 17.4 | 16.2–19.4 | 17.7 | 0.9 |
Body width under dorsal-fin origin | 15.2 | 13.8–17.2 | 15.6 | 1.0 |
Head width | 21.7 | 18.0–22.0 | 19.6 | 1.3 |
Pectoral spine length | 9.7 | 7.9–10.8 | 9.8 | 0.7 |
Dorsal spine length | 8.9 | 6.9–9.7 | 8.6 | 0.7 |
Caudal-fin length | 21.0 | 16.3–21.3 | 18.7 | 1.2 |
Maxillary-barbel length | 23.6 | 17.8–26.9 | 22.7 | 2.4 |
Nasal-barbel length | 18.4 | 14.1–18.9 | 16.3 | 1.6 |
Outer-mental barbel length | 13.4 | 10.0–16.2 | 13.2 | 2.0 |
Inner-mental barbel length | 9.6 | 7.4–11.2 | 9.1 | 1.2 |
For genomic DNA analysis, a piece of pectoral fin was dissected from the specimen and stored in 100% ethyl alcohol. Next, total DNA was extracted with the genomic DNA Prep Kit for blood and tissue (QUIAGEN Co., USA). The mitochondrial cytochrome b gene was amplified by PCR using the method of
Molecular analysis was performed using the cytochrome b (cytb) sequences of seven newly obtained populations of L. geumgangensis, and data from 36 other Siluriformes specimens, including the genus Liobagrus, which are closely related. Sequence data of species other than L. geumgangensis were downloaded from the National Center for Biotechnology Information (NCBI) GenBank (Table
List of mitochondrial cytb sequences newly obtained in this study and downloaded from GenBank with information on collection sites in South Korea and country of origin.
Species | Location of voucher specimens | GenBank Accession No. | Remarks in Fig. |
---|---|---|---|
Ameiurus catus | USA | MG570433 | |
Ameiurus melas | China | KT804702 | |
Ameiurus natalis | USA | MG570406 | |
Hemibagrus guttatus | China | KJ458934 | |
Hemibagrus macropterus | China | JF834542 | |
Hemibagrus nemurus | Malaysia | KJ573466 | |
Hemibagrus spilopterus | Cambodia | JQ343983 | |
Horabagrus brachysoma | India | KU870467 | |
Ictalurus furcatus | USA | KM576102 | |
Ictalurus pricei | Mexico | KJ496298 | |
Leiocassis crassilabris | China | JX867257 | |
Liobagrus andersoni | South Korea | NC032035 | |
Liobagrus anguillicauda | China | JQ026256 | |
Liobagrus geumgangensis | South Korea (Cheongyang) | OP980981 (this study) | 1 |
South Korea (Gongju) | OP980982 (this study) | 2 | |
South Korea (Boeun) | OP980984 (this study) | 3 | |
South Korea (Youngdong) | OP980985 (this study) | 4 | |
South Korea (Muju) | OP980983 (this study) | 5 | |
South Korea (Jinan) | OP980986 (this study) | 6 | |
South Korea (Gosan) | OP945750 (this study) | 7 | |
Liobagrus hyeongsanensis | South Korea | MZ066608 | |
Liobagrus kingi | China | KC193779 | |
Liobagrus marginatoides | China | KC473938 | |
Liobagrus marginatus | China | NC022923 | |
Liobagrus mediadiposalis | South Korea | KR075136 | |
South Korea (Sancheong) | OP980987 (this study) | 8 | |
Liobagrus nigricauda | China | KC316116 | |
Liobagrus obesus | South Korea | DQ321752 | |
Liobagrus reini | Japan | AP012015 | |
Liobagrus somjinensis | South Korea | MN756661 | |
Liobagrus styani | China | KX096605 | |
Noturus taylori | USA | KP013089 | |
Ompok bimaculatus | India | KY887474 | |
Ompok pabda | Bangladesh | MK007074 | |
Pelteobagrus eupogon | China | KJ001784 | |
Pelteobagrus fulvidraco | China | HM641815 | |
Pelteobagrus nitidus | China | HM746659 | |
Silurus asotus | China | JX087351 | |
Silurus lanzhouensis | China | JF895472 | |
Silurus meridionalis | China | HM746661 | |
Silurus microdorsalis | South Korea | KT350610 |
Geum River, Korea.
Holotype. CNUC 39103, 70.7 mm SL, male, Geum River, Namyang-myeon, Cheongyang-gun, South Korea. 36°23'41.66"N, 126°48'41.30"E, collected by J.Y. Park, S.W. Yun and H.T. Kim using a scoop net, 14 March 2018 (Fig.
Liobagrus geumgangensis can be distinguished from other species in the genus by the length of the upper and lower jaws, and the presence or absence of serrations on the posterior edge of the pectoral fin, which are representative characteristics of the genus Liobagrus. Liobagrus geumgangensis has a longer upper than lower jaw and serrations on the posterior edge of the pectoral fin. Species that share these characteristics with L. geumgangensis are as follows: L. mediadiposalis, L. somjinensis, L. hyeongsanensis, L. huaiheensis and L. pseudostyani. This new species can be distinguished by the relatively large number of serrations (5–8) on the posterior edge of the pectoral fin (vs. 4–6 in L. mediadiposalis and L. somjinensis, 2–3 in L. hyeongsanensis, L. huaiheensis and L. pseudostyani). It can be further differentiated from L. huaiheensis and L. pseudostyani by the subtruncate caudal fin (vs. rounded). Liobagrus geumgangensis is distinguished from its geographically closest congeners L. mediadiposalis and L. somjinensis by the following combination of characteristics: the body and fins are dark yellow, and the margins of the dorsal, anal, and caudal fins are dark brown, but the outermost rim is faintly yellow (vs. broad yellowish outer margin of the fins in L. mediadiposalis and crescent-shaped band in the middle of the caudal fin in L. somjinensis); pectoral fin rays I, 8 (vs. both I, 7); caudal fin rays 52–56 (vs. both 57–61); a relatively short occiput to dorsal-fin origin (6.9–9.8% SL vs. 10.3–13.3% in L. mediadiposalis and 9.7–13.0 in L. somjinensis); a short pelvic-fin origin to anal-fin origin (11.9–17.3% SL vs. 15.3–20.9% in L. mediadiposalis and 13.3–18.7% in L. somjinensis); a long dorsal-fin base (10.6–13.5% SL vs. 7.7–10.4% in L. mediadiposalis and 8.8–11.3% in L. somjinensis); and 8–9 gill rakes (vs. 7–11 in L. mediadiposalis and 7–9 in L. somjinensis) (Figs
Counts and measurements, expressed as percentages of SL, are given in Table
Mouth terminal; lips thickened and papillate, premaxillary and mandibular toothpads curved, teeth small and ciliform or setiform, with upper jaw slightly longer than lower jaw. Four pairs of barbels; maxillary barbel longest, reaching to base of pectoral-fin spine; nasal barbel short, not reaching to posterior margin of preoperculum; outer mental barbel long, reaching to posterior edge of pectoral-fin base; inner-mental barbel shortest among four pairs of barbels, about half length of outer mental barbel, reaching to gill membrane. Body compressed and round, head depressed and caudal peduncle strongly compressed; dorsal and ventral profiles straight. Predorsal profile slightly sloping ventrally from dorsal fin to occiput. Eye smaller, dorsolateral, subcutaneous, ovoid. Snout rounded in dorsal view. Anterior nostril tubular, rim with a fleshy flap forming a short tube; posterior nostril porelike, rim posteriorly confluent with base of nasal barbel. Gill membranes narrowly joined at isthmus. Lateral line absent or vestigial.
See Fig.
The adductor mandibulae in males is somewhat swollen during the spawning season, from late April to June.
Named after the Geum River (Geumgang in Korean), the type locality. We propose the Korean name Geumgang-Jagasari for this species.
Liobagrus geumgangensis sp. nov. is restricted to some rivers flowing to the west coast of South Korea: Geum River and upper stream of Mangyeong River (Fig.
Liobagrus geumgangensis is nocturnal and benthic. They inhabit the bottom stratum of large and small stone or pebble substratum in shallow waters, about 0.3–0.6 m deep, with running waters with moderately fast currents. The spawning season is from late April to June. The adult females reach up to 99.8 mm SL and lay eggs 2.5–3.0 mm (2.8±0.1) in diameter. The adult males guard their fertilized egg. They feed mostly on aquatic insect larvae such as those of the Trichoptera, Ephemeroptera and Diptera.
As a result of the cytb gene analysis, we confirm that samples from Liobagrus geumgangensis form an independent group distinct from the closely related species L. mediadiposalis and L. somjinensis. Kimura’s 2-parameter distance analysis revealed genetic distances ranging from 0.2% to 2.3% within groups of L. geumgangensis populations. We found the genetic distance between L. geumgangensis and L. somjinensis to be 4.7% to 5.0%, which was smaller compared to that observed with L. mediadiposalis (5.8% to 6.1%; Fig.
Compared with the original descriptions of Liobagrus (
Comparisons of major diagnostic characters of Liobagrus species distributed in Korea and neighboring countries.
Character | L. geumgangensis | L. mediadiposalis | L. andersoni | L. obesus | L. somjinensis | L. hyeongsanensis | L. reini | L. formosanus | L. nigricauda | L. marginatoides |
Upper/lower jaw in length | >1 | >1 | =1 | =1 | >1 | >1 | >1 | =1 | =1 | <1 |
Caudal fin shape | Subtruncate | Subtruncate | Subtruncate | Subtruncate | Subtruncate | Subtruncate | Rounded | Rounded | Rounded | Subtruncate |
Number of serrations on the pectoral fin | 5–8 | 4–6 | 0–3 | 3–5 | 4–6 | 2–3 | 0 | 0 | 0 | 0 |
Occiput to dorsal-fin origin | 6.9–9.8 | 10.3–13.3 | 8.5–12.4 | 9.4–15.1 | 9.7–13.0 | 9.3–12.9 | 8.3–9.4 | 7.2–10.2 | 7.6–13.3 | 8.8–11.6 |
Pelvic-fin origin to anal-fin origin | 11.9–17.3 | 15.3–20.9 | 11.9–17.0 | 9.6–14.1 | 13.3–18.7 | 12.1–16.6 | 12.7–15.3 | 13.5–19.1 | 12.1–16.4 | 13.6–17.9 |
Dorsal-fin base length | 10.6–13.5 | 7.7–10.4 | 10.3–15.2 | 12.4–16.0 | 8.8–11.3 | 7.8–10.9 | 10.6–12.7 | 11.0–14.4 | 6.3–12.0 | 11.0–14.4 |
Character | L. styani | L. marginatus | L. anguillicauda | L. aequilabrisa | L. chenghaiensisb | L. kingic | L. huaiheensisd | L. chengduensise | L. pseudostyanie | L. brevispinaf |
Upper/lower jaw in length | >1 | <1 | =1 | =1 | ≤ 1 | ≤ 1 | >1 | <1 | >1 | =1 |
Caudal fin shape | Rounded | Subtruncate | Rounded | Rounded | Subtruncate | Rounded | Rounded | Rounded | Rounded | Rounded |
Number of serrations on the pectoral fin | 0 | 3–4 | 0 | 0 | 2–5 | 2–4 | 2–3 | 3–4 | 2–3 | 0 |
Occiput to dorsal-fin origin | 5.8–11.4 | 8.8–12.1 | 8.0–10.7 | – | – | – | – | – | – | – |
Pelvic-fin origin to anal-fin origin | 10.3–14.1 | 12.3–17.2 | 12.0–14.6 | – | – | – | – | – | – | – |
Dorsal-fin base length | 8.2–12.7 | 10.8–15.3 | 8.5–10.7 | – | – | – | – | – | – | – |
To summarize, within the Liobagrus distribution in Korea, it is noteworthy that L. geumgangensis is the only species with an upper jaw longer than the lower jaw and I, 8 pectoral fin rays. In addition, L. geumgangensis differs from L. somjinensis in several characters: absence vs. presence of a broad vertical yellowish crescent-shaped band on the caudal fin, with a deep black outer margin; 5–8 vs. 4–6 serrations on the pectoral fin; and 52–56 caudal fin rays vs. 57–61 (Fig.
Liobagrus geumgangensis is allopatrically distributed in restricted river systems, the Geum River and a patch of the Mangyeong River, which flow toward the western coast of Korea. Unlike other Liobagrus species, L. somjinensis is restricted to rivers flowing to the west coast and Geogeum Island, the Somjin, Dongin and Tamjin rivers. Liobagrus hyeongsanensis has a much smaller distribution including the Hyeongsan River flowing into the east coast, whereas L. mediadiposalis is found only in the Nakdong River on the west coast (Fig.
Our results are consistent with a recent study by
Phylogenetic tree using maximum likelihood (ML) method based on mitochondrial cytochrome b gene sequences of Siluriformes species including L. geumgangensis. Bootstrap support values based on 1000 replicates are displayed on each node as >50. The blue color of the branches indicates L. geumgangensis.
The geographical isolation of the freshwater fish of South Korea is likely related to the geological origins of the Korean Peninsula. The Korean Peninsula was formed by active orogeny movements from the early Triassic to the Jurassic. The structure of the current complex topography is due to the tectonic shift concentrated in the Tertiary Period of the Cenozoic Era. As a result, Korea has an approximately 1400 km long mountainous region stretching from North Korea to South Korea. The peninsula, called the Baekdudaegan, contains at least 12 mountain ranges that have formed unique rivers, including the Han, Geum, Nakdong, Hyeongsan, and Mangyeong rivers (
According to
1 | The length of both jaws is the same, and the mouth is in front of the snout | 2 |
– | The length of both jaws is different, the lower jaw is shorter than the upper jaw, and the mouth is located below the snout | 3 |
2 | The pectoral fin spines have 0–3, and the adults have small and traces | L. andersoni |
– | The spines of the pectoral fin are 3–5, and the spines of the adult are large and clear | L. obesus |
3 | There are no bright bands on the edges of the dorsal fin, anal fin, caudal fin, and adipose fins, while a crescent-shaped bright band appears in the center of the caudal fin | L. somjinensis |
– | The dorsal fin, anal fin, caudal fin, and adipose fin have bright colored bands, while there is no crescent-shaped bright band in the center of the caudal fin | 4 |
4 | The edges of the anal fin, caudal fin, and adipose fin have a bright band. The pectoral fin spines are long (more than 7% of the standard length), and the dorsal fin spines are also long (more than 5% of the standard length) | 5 |
– | There are narrow or almost no light-colored bands along the edges of the anal, caudal and adipose fins. The length of the pectoral fin spines is short (less than 6% of the standard length), and the length of the dorsal fin spines is also short (more than 4% of the standard length) | L. hyeongsanensis |
5 | A wide band of bright color appears on the edge of each fin, the number of rays of the pectoral fin is I, 7, and the distance between the origin of the pelvic fin and the origin of the anal fin is long (more than 17% of the standard length) | L. mediadiposalis |
– | There is a bright band at the edge of each fin, but the width is narrow. The number of rays of the pectoral fin is I, 8, and the distance between the origin of the pelvic fin and the origin of the anal fin is short (less than 15% of standard length) | L. geumgangensis sp. nov. |
Liobagrus andersoni: CNUC 9441–3, 3 specimens, 86.3–90.9 mm SL, Bongpyeong-myeon, Pyeongchang-gun, Gangwon-do, Han River, South Korea; CNUC 39021, 1 specimen, 71.5 mm SL, Cheongchen-myeon, Goesan-gun, Chungcheongbuk-do, Han River, South Korea. CNUC 38753–38778, 26 specimens, 81.4–105.5 mm SL, Gasoo-ri, Jeongseon-eup, Jeongseon-gun, Gangwon-do, Han River, South Korea.
Liobagrus obesus: CNUC 936–40, 5 specimens, 58.2–81.8 mm SL, Simcheon-myeon, Yeongdong-gun, Chungcheongbuk-do, Geum River, South Korea: CNUC 9434, 9436, 9439, 3 specimens, 82.3–94.8 mm SL, Simcheon-myeon, Yeongdong-gun, Chungcheongbuk-do, Geum River, South Korea: CNUC 39022, 1 specimen, 95.5 mm SL, Gosan-myeon, Gosan-gun, Jeollabuk-do, Mankyeong River, South Korea.
Liobagrus mediadiposalis: CNUC 37821–38, 18 specimens, 73.9–100.3 mm SL, Sicheon-myeon, Sancheong-gun, Gyeongsangnam-do, Nakdong River, South Korea: CNUC 1019–20, 2 specimens, 55.6–64.7 mm SL, Imgok-dong, Gwangsan-gu, Gwangju, Yeongsan River, South Korea: CNUC 1025–8, 4 specimens, 78.9–108.9 mm SL, Hamyang-gun, Gyeongsangnam-do, Nakdong River, South Korea: CNUC 1035–8, 4 specimens, 82.4–109.5 mm SL, Yurim-myeon, Hamyang-gun, Gyeongsangnam-do, Nakdong River, South Korea: CNUC 1801–5, 5 specimens, 83.4–107.8 mm SL, Macheon-myeon, Hamyang-gun, Gyeongsangnam-do, Nakdong River, South Korea: CNUC 1806–8, 3 specimens, 81.9–102.6 mm SL, Cheoncheon-myeon, Jangsu-gun, Jeollabuk-do, Geum River, South Korea: CNUC 1809, 1 specimen, 89.4 mm SL, Samcheok-si, Gangwon-do, Samcheokoship Stream, South Korea: CNUC 9445, 1 specimen, 123.7 mm SL, Mungyeong-eup, Mungyeong-si, Gyeongsangbuk-do, Nakdong River, South Korea: CNUC 39153, 1 specimen, 97.0 mm SL, Sicheon-myeon, Sancheong-gun, Gyeongsangnam-do, Nakdong River, South Korea.
Liobagrus somjinensis: CNUC 37749, 1 specimen, 99.4 mm SL, Geumji-myeon, Namwon-si, Jeollabuk-do, Somjin River, South Korea: 37750–65, 16 specimens, 74.1–100.6 mm SL, Geumji-myeon, Namwon-si, Jeollabuk-do, Somjin River, South Korea: CNUC 37766–9, 4 specimens, 74.8–91.3 mm SL, Jukgok-myon, Gokseong-gun, Jeollanam-do, Somjin River, South Korea: CNUC 39170, 1 specimen, 99.4 mm SL, Sikjeong-dong, Namwon-si, Jeollanam-do, Somjin River, South Korea.
L. hyeongsanensis: CNUC 38547, 1 specimen, 84.1 mm SL, Yangbuk-myeon, Gyeongju-si, Hyeongsan River, South Korea: CNUC 38548–38567, 20 specimens, 57.1–84.1 mm SL, Yangbuk-myeon, Gyeongju-si, Hyeongsan River, South Korea: CNUC 38830–38854, 25 specimens, 41.8–67.8 mm SL, Hwangnyong-dong, Gyeongju-si, Bukcheon River, South Korea.
L. geumgangensis (for gill raker analysis): CNUC 39138–39142, 39170–39184, 20 specimens, 60.2–95.7 mm SL, Namyang-myeon, Cheongyang-gun, Chungcheongbuk-do, Geum River, South Korea.
L. reini: CNUC 38971–38972, 2 specimens, 48.9–64.5 mm SL, Sanda, Hyogo Prefecture, Japan.
L. formosanus: NTHUB 01763, 7 specimens, 56.6–86.4 mm SL, Puli, Nantou County, Taiwan; NTHUB 01766, 1 specimen, 73.3 mm SL, Changhua County, Taiwan.
L. nigricauda:
L. marginatoides:
L. styani:
L. marginatus:
L. anguillicauda:
We thank Prof. H. T. Kim at Jeonju National University of Education, Jeonju, South Korea, and Mr. J. U. Kim at Jeonbuk National University, Jeonju, South Korea for collecting samples from several streams.
The authors have declared that no competing interests exist.
No ethical statement was reported.
No funding was reported.
Su-Hwan Kim and Seung-Woon Yun wrote the text and made the figures. Seung-Woon Yun and Jong Young Park edited and approved the manuscript for publication.
Su-hwan Kim https://orcid.org/0000-0003-4831-5071
Seung-woon Yun https://orcid.org/0000-0003-0893-4468
Jong-young Park https://orcid.org/0000-0003-2348-5111
All of the data that support the findings of this study are available in the main text.