Saturday, July 16, 2022

[Ichthyology • 2022] Pegasus sinensis • A New Seamoth Species of Pegasus (Syngnathiformes: Pegasidae) from the East China Sea

Pegasus sinensis
Zhang, Zhang, Ma, Liu, Lin & Wang, 2022

Chinese Seamoth  |  中华海蛾鱼  ||  DOI: 10.24272/j.issn.2095-8137.2022.109
Photos by Xin Wang.

The Pegasidae family, which includes seven species of seamoths, is widely distributed in the temperate and tropical waters of the Indo-Pacific, ranging from South Africa to Hawaii. In this study, we describe a new species of seamoth, Pegasus sinensis sp. nov., based on morphological and molecular characterization of 14 specimens collected from the surrounding waters of Xiamen City, Fujian Province, China. The new species differs from closely related P. volitans in both the density and color of spots present on the dorsal and lateral body surfaces. Based on the mitochondrial genomes (mitogenomes) of three newly sequenced pegasids used in this study, we conducted a phylogenetic analysis of Pegasidae, revealing that Pegasus sinensis sp. nov. and P. volitans diverged from their common ancestor approximately 9.0 million years ago (Ma). Two members of the pegasid genus Spinipegasus (S. laternarius and S. nanhaiensis) clustered outside the monophyletic branch of Pegasus and Eurypegasus, supporting the classification of Spinipegasus as a valid genus, as proposed in previous studies.

   Sampling sites, holotype, and phylogeny of Pegasus sinensis sp. nov.
A: Sampling sites of Pegasus sinensis sp. nov. (red circles).
B–D: Dorsal, lateral, and ventral views of Pegasus sinensis sp. nov. (TMBC030944). Photos by Xin Wang.
 E: Bayesian phylogram of Pegasidae inferred from mitogenome sequences. 
F: Bayesian phylogram of Pegasidae inferred from mitochondrial 16S rDNA.

B–D: Dorsal, lateral, and ventral views of Pegasus sinensis sp. nov. (TMBC030944).
Photos by Xin Wang.

Pegasus sinensis sp. nov.

Diagnosis: Pegasus sinensis sp. nov. can be distinguished from all known congeners based on a combination of the following characters (see Supplementary Table S2 for details, with P. volitans, P. tetrabelos, S. laternarius, and S. nanhaiensis data taken from Osterhage et al., 2016; Zhang et al., 2020): (1) tail rings 12 (I–XII) (vs. 11 in S. laternarius and S. nanhaiensis); (2) body slender, similar to P. volitans, carapace width 14.44%–18.15% of SL (vs. 28.8%–37.0% of SL in S. nanhaiensis and 24.7%–32.2% of SL in S. laternarius); (3) rostrum length 21.01%–25.53% of SL (vs. 4.8%–17.4% of SL in S. nanhaiensis and 7.5%–19.9% of SL in S. laternarius; (4) pectoral fin rays 11 (vs. 10 in P. tetrabelos); (5) tail length 60.44%–65.76% of SL (vs. 59.3%–65.2% of SL in P. tetrabelos and 45.1%–52.8% of SL in S. nanhaiensis); (6) overlaid large, dark spots (vs. smaller brown to dark brown spots in P. volitans and P. tetrabelos); and (7) dorsal plate pairs 3 (d1–3), dorsolateral plate pairs 4 (dl1–4), ventrolateral plate pairs 5 (vl1–5), caudodorsal plate pairs at tail 11, and caudoventral plate pairs 11 (Figure 1B–D).
Etymology: The species name sinensis is derived from its currently known distribution in the coastal waters of China.
Suggested English name: Chinese Seamoth
Suggested Chinese common name: 中华海蛾鱼 
(Chinese phonetic alphabet: zhōng huá hǎi é yú).

 Ying-Yi Zhang, Rong-Rong Zhang, Shao-Bo Ma, Shuai-Shuai Liu, Qiang Lin and Xin Wang. 2022. A New Seamoth Species of Pegasus (Syngnathiformes: Pegasidae) from the East China Sea. Zoological Research. 43(4); 675-678. DOI: 10.24272/j.issn.2095-8137.2022.109