Hippocampus coronatus Temminck & Schlegel, 1850

Han, Sang-Yun, Kim, Jin-Koo, Kai, Yoshiaki & Senou, Hiroshi, 2017, Seahorses of the Hippocampuscoronatus complex: taxonomic revision, and description of Hippocampushaema, a new species from Korea and Japan (Teleostei, Syngnathidae), ZooKeys 712, pp. 113-139 : 114-119

Hippocampus coronatus Temminck & Schlegel, 1850 Figs 3F G, 4B, 5C, 6B, 6E, Tables 2, 3

Hippocampus coronatus Temminck and Schlegel 1850: 274, pl. 120 (fig. VII) (Lectotype: RMNH.PISC.D 1543; Paralectotype: RMNH.PISC.D 1544; type locality: Japan; Boeseman 1947: 196); Kaup 1853: 229; Jordan and Snyder 1901: 18; Matsubara 1955: 431; Jordan et al. 1913: 100; Boeseman 1947: 195; Burgess and Axelrod 1972: 212; Araga 1984: 89; Senou 1993: 489, 1294; Lourie et al. 1999: 88; Mukai et al. 2000: 139; Senou 2000: 536; Senou 2002: 536, 1508; Lourie et al. 2004: 42; Yoshino and Senou 2008: 76; Kuiter 2009: 129; Kohno et al. 2011: 127; Senou 2013: 635, 1911; Lourie 2016: 106; Lourie et al. 2016: 21.

Material examined.

Japan. RMNH.PISC.D 1543 (lectotype of H. coronatus , photograph from RMNH), female, 103.3 mm SL, von Siebold collection. RMNH.PISC.D 1544 (paralectotype of H. coronatus , photograph from RMNH), female, 100.2 mm SL, von Siebold collection. FAKU 137348 137351, 4, 96.4 112.6 mm SL, Miura, Kanagawa, Nov 2014, H. Sugawara. KAUM-I 20721, 1, 73.7 mm SL, Takane, Hamasa, Tateyama, Chiba, 34°58'38"N; 139°47'19"E, depth 20 m, 2 Dec 2008, M. Aizawa. KPM-NI 1375, 1, 82.0 mm SL, 6 Sep 1964. KPM-NI 7301 7302, 2, 110.5 117.9 mm SL, depth 4 m, 12 Jul 2000; KPM-NI 7535, 1, 124.1 mm SL, 19 Dec 2000, S. Gosho; KPM-NI 7718 7720, 3, 113.1 115.6 mm SL, depth 1 12 m, 18 Jan 2001, S. Gosho; KPM-NI 8075, 1, 115.3 mm SL, depth 3 4 m, 26 Jul 2001, K. Uchino & D. Kanbayashi; in front of Misaki Marine Biological Station, The University of Tokyo, Aburatsubo Bay, Koajiro, Miura, Kanagawa. KPM-NI 14854, 1, 24.1 mm SL, in front of Keikyu Aburatsubo Marine Park, Koajiro, Miura, Kanagawa, T. Mukai. KPM-NI 19270, 1, 113.7 mm SL, Cape of Manazuru, Obaradai, Yokosuka, Kanagawa, 1 Jul 2000, T. Yokoo. KPM-NI 19272, 1, 108.5 mm SL, Kannonzaki, Tatara-hama, Obaradai, Yokosuka, Kanagawa, 12 Dec 1998, T. Yokoo. KPM-NI 18765, 18772, 2, 27.8 28.4 mm SL, 14 Jun 2006, Y. Miyazaki; KPM-NI 21540, 1, 39 mm SL, 6 Jul 2003; KPM-NI 21541, 1, 53.4 mm SL; 19 Jun 2004; KPM-NI 25371, 1, 103.5 mm SL, depth 7 m, 27 Jun 2009, S. Shimizu; in front of Tateyama Station of Field Science Center, Tokyo University of Marine Science and Technology, Banda, Tateyama, Chiba. KPM-NI 27901 27903, 3, 51.4 67.5 mm SL, 2 6m depth, 5 Oct 2010, N. Takeuchi; KPM-NI 29380, 1, 47.8 mm SL, depth 2 6 m, 3 Jun 2011, N. Takeuchi; Gouchome, Shimoda, Shizuoka. KPM-NI 30596, 1, 133.0 mm SL, Sagami bay, Kanagawa Hadano High School, Kanagawa.

Diagnosis.

A species of Hippocampus having a bony body; double gill openings; ring (R: TrR + TaR) 10 + 37 40, mode 10 + 39 (lectotype: 10 + 38); extremely high coronet, straight or inclined backwards; CoT 4; CHGO 43.0 60.1 % HL; CHMC 55.7 79.0 % HL; WS thick and recurved.

Description.

Head and trunk folded at approximately right angle; snout elongated and fused; pelvic and caudal fins absent; prehensile tail; D 12 15, mode 14 (lectotype: 14); A 4; P 10 13, mode 12 (lectotype: 12); D always greater than or equal to P; CS 1; ES 1; SnL 35.6 44.2 % HL; ED 32.3 62.9 % SnL; HL 56.6 71.3 % TrL; TrL 42.6 64.5 % TaL; flat and smooth skin generally covering armor-plated body; ACS degenerative; Coa expanded; CoT 4 arising from degenerative PCS; WS two fused LTrRDS (lower more developed than upper and recurved; upper LTrRDS occasionally standing out [Fig. 6E]); dorsal and lateral spines more prominent on 1st, 4th, 7th, and 10thTrR than on other TrRs, except occasionally for lateral spines on 10thTrR, occasionally; usually no skin filaments on body, but, occasionally, a strand was observed on ACS or on the forward part of Coa; blunt (or absent) body spine; often whitish radial blotches from iris to surrounding eye and striped-pattern body; occasionally semicircular band present on dorsal fin; variable color, light to dark red-brown or yellow, sometimes showing numerous thin whitish striations and/or dark small dots along body; male brood pouch sometimes speckled with fine white and dark spots ( Kuiter 2009); no particular sexual dimorphism, apart from male brood pouch.

Distribution.

Southeastern coast of Honshu (Japan), from Izu Peninsula (Shizuoka Prefecture) to Boso Peninsula (Chiba Prefecture) (Fig. 1). Hippocampus coronatus lives in weed habitats, especially in floating Sargassum ( Kuiter 2009; Senou 2013), within shallow areas (0 20 m depth).

Etymology.

The Latin word coronatus means crowned. The new Korean name, Wanggwan-haema means crowned seahorse, in agreement with the English and scientific names. In fact, Haema, which has the connotation common and fish species belonging to the genus Hippocampus in Korean, has been used to name seahorses commonly found in Korea, whereas Wanggwan-haema has been informally used to refer to H. coronatus in Korean. In addition, the word wanggwan [crown] is more suited for H. coronatus , whose coronet is considerably higher than that of H. haema . The Japanese name Tatsu-no-otoshigo literally means dragon s bastard child.

Remarks.

Temminck and Schlegel (1850) described H. coronatus based on five specimens. Boeseman (1947) designated one of these specimens RMNH.PISC.D 1543 as the lectotype. As a consequence the other three specimens RMNH.PISC.D 1541, RMNH.PISC.D 1542, and RMNH.PISC.D 1544 became paralectotypes, except that RMNH.PISC 3924 was reidentified as H. mohnikei (see remarks of H. sindonis below). However, two of the specimens described in Boeseman (1947), RMNH.PISC.D 1541 and 1542, have a moderately high coronet, not agreeing with the H. coronatus described in the present study and being more similar to H. haema (see species description below). The lectotype RMNH.PISC.D 1543 and the paralectotype RMNH.PISC.D 1544 have an extremely high coronet, which agrees with the present description of H. coronatus . Our 28 specimens have an extremely high coronet, a wing-tip spine on the dorsal fin base, and CoT 4, as described and illustrated in Temminck and Schlegel (1850). The phylogenetic trees obtained in the present study also support the differentiation of these 28 specimens from H. sindonis and H. haema (Fig. 7).

The type series does not match Temminck and Schlegel (1850) s description on the basis of five dried specimens and an illustration which was based on a small male seahorse ( Temminck and Schlegel 1850; Kaup 1853). The lectotype (RMNH.PISC.D 1543) and the paralectotype (RMNH.PISC.D 1544) are large female seahorses (100.2 103.3 mm SL), and RMNH.PISC.D 1541, 1542, and RMNH.PISC 3924 are small female seahorses (67.5 74.0 mm SL). RMNH.PISC 3924 is preserved in spirits unlike the other specimens, therefore Boeseman s inclusion of this sample is questionable. The original illustration of H. coronatus from Temminck and Schlegel (1850) might be the missing fifth dry specimen (personal communication, M. van Oijen).

The type locality of H. coronatus has not been established. Although it is thought to be Nagasaki ( Eschmeyer et al. 2017), no specific locality information is provided for the type series or in previous studies ( Temminck and Schlegel 1850; Boeseman 1947; Lourie et al. 1999). Seahorses are used historically as charm for safe-birth in East Asia (Korea, Japan, and China) and as a trinket in western culture ( Lourie et al. 1999; Scales 2009). Thus, we cannot exclude the possibility that dried specimens might be from someone s folkloric collection (MacLean, 1973). This historical element might support that the type series was not caught in the Nagasaki area. Therefore, it is possible that collectors not only gathered specimens from Nagasaki, but Edo (present-day Tokyo) as well, which is the habitat of H. coronatus in this study (see Fig. 1; personal communication, M. van Oijen; MacLean 1973; Compton and Thujsse 2013; Nofuji et al. 2013).

Although H. coronatus sensu stricto was considered to be distributed along the coast of Japan and southern coast of Korea, we only found records from the Pacific Ocean. Mori (1928) reported H. coronatus off Korea for the first time, but the original data consisted only of checklists, not providing descriptions; thus, Mori (1928) might be reporting the occurrence of H. haema or H. coronatus . Therefore, the distribution of H. coronatus needs to be reviewed. In Korea and Japan, seahorse identification has been generally treated as a laborious task, leading to taxonomic controversy and misidentifications; thus, we recommend a careful revision of H. coronatus recorded from Korea and Japan.

Senou (2002) and (2013) suggested that the publication date for H. coronatus was in 1847. However, based on Sherborn and Jentick (1895), Boeseman (1947), Mees (1962), Bauchot et al. (1982), and Eschmeyer et al. (2017), the year should be 1850.