Description of a new cryptic, shallow‐water tonguefish (Pleuronectiformes: Cynoglossidae:Symphurus) from the western North Pacific Ocean

Abstract

Combined results based on morphological characters and analyses of partial sequences of the 16s rRNA and coI genes confirm the validity of a new, cryptic, symphurine tonguefish from the western North Pacific Ocean. Symphurus leucochilus n. sp., a diminutive species reaching sizes to c. 67 mm standard length, is described from nine specimens that were collected from fish-landing ports and from trawls made at c. 150 m off Taiwan and Japan. Symphurus leucochilus shares many similar features with those of Symphurus microrhynchus and that of several undescribed species that are morphologically similar to S. microrhynchus. Symphurus leucochilus has also been misidentified as Symphurus orientalis in fish collections because of shared similarities in some aspects of their morphology. The new species differs from all congeners by the following combination of meristic, morphological and pigmentation features: a predominant 1-2-2-2-2 pattern of interdigitation of proximal dorsal-fin pterygiophores and neural spines; 12 caudal-fin rays; 89-92 dorsal-fin rays; 76-80 anal-fin rays; 49-51 total vertebrae; four hypurals; 75-83 longitudinal scale rows; 32-35 transverse scales; 15-17 scale rows on the head posterior to the lower orbit; absence of a fleshy ridge on the ocular-side lower jaw and a membranous connection between the anterior nostril and lower part of the eye; a narrow interorbital space and dorsal-fin origin anterior to the vertical through the anterior margin of the upper eye; absence of both dermal spots at bases of anterior dorsal-fin rays and melanophores on the isthmus; uniformly yellow to light-brown ocular-side colouration without bands; dorsal and anal fins with alternating series of dark rectangular blotches and unpigmented areas; a uniform white blind side and a bluish-black peritoneum. Despite overall similarities in morphology between S. leucochilus and S. orientalis, as well as between two of the nominal species morphologically similar to S. microrhynchus, analyses of partial 16s rRNA and coI gene sequences show that S. leucochilus, S. orientalis and the two other nominal species represent three distinct lineages within the genus Symphurus.

Sequence Variations and Phylogeny Relationships Among Seven River Nile Teleosti Species from Qena, Egypt Based on Mitochondrial 16S Rrna Gene Sequences

“…The mtDNA 16S rRNA gene primers were sensitive and successfully amplified the targeted DNA fragments for each species. Similar 16S regions generated fragments by the same primer pair in other species have been reported (Lee et al, 2014;Quraishi et al, 2015;Carvalho et al, 2004).…”

Unraveling cryptic diversity among shallow-water tonguefishes (Pleuronectiformes: Cynoglossidae: Symphurus) from the Indo-West Pacific region, with descriptions of five new species

“…They considered S. microrhynchus to be a widespread species, but new data (see below) reveals that at least five other species were included in their account for S. microrhynchus. Lee et al (2014; also confirmed that more than a single species was present among material identified as S. microrhynchus in Munroe & Marsh (1997). In fact, among specimens examined by Munroe & Marsh (1997), approximately six nominal species (including S. holothuriae) were included.…”

“…Approximately 31 nominal species of Symphurus are distributed in the Indo-Pacific region, most of which are deepwater species (Alcock 1891;Norman 1939;Chabanaud 1955a;Munroe 1992;Krabbenhoft & Munroe 2003;Munroe & Hashimoto 2008;Lee et al 2009a;2009b;Munroe et al 2011;Lee et al 2013;2014). Among species of Symphurus reported from the Indo-Pacific region, only five have been recorded from depths shallower than 200 m. This assemblage of shallow-water species of Symphurus comprises four characterized by having 12 caudal-fin rays: S. microrhynchus (Weber, 1913), the first described species of shallow-water tonguefish reported from the Indo-West Pacific region (Weber 1913;Chabanaud 1955b;Munroe & Marsh 1997;Lee et al 2013;2014;; S. holothuriae Chabanaud, 1948, a species collected off western Australia and known only from the holotype, and considered a possible junior synonym of S. microrhynchus (Weber, 1913) by Chabanaud (1955b) and regarded as a junior synonym of S. microrhynchus by Munroe & Marsh (1997); S. leucochilus Lee et al 2014, a species formerly frequently misidentified as S. orientalis (Bleeker, 1879) and one with meristic features that overlap those of S. microrhynchus and related species (Lee et al 2014;; and S. longirostris Lee et al 2017, a species recently described from Japanese waters whose meristic features are similar to, or overlap those of, S. microrhynchus and related species. Among Indo-Pacific Symphurus, 14 nominal species, including five nominal species described in this study, have 12 caudal-fin rays (Alcock 1891;Chabanaud 1948;1955b;1957;Munroe & Marsh 1997;Munroe 2001;Lee et al 2013;2014).…”

“…Lee et al (2013) in their work redescribing S. orientalis discovered that morphological data used in earlier studies to diagnose this species from congeners actually included meristic data from specimens previously identified as S. orientalis, but having lower meristic values as the same as those of S. microrhynchus (sensu Munroe & Marsh 1997). Lee et al (2014) described these specimens as S. leucochilus, a shallow-water species from the western North Pacific. From their examination of specimens featuring low counts of meristic features, including holotypes of S. microrhynchus and S. holothuriae, Lee et al (2014) also discovered that the species concept of S. microrhyn-…”

“…Lee et al (2014) described these specimens as S. leucochilus, a shallow-water species from the western North Pacific. From their examination of specimens featuring low counts of meristic features, including holotypes of S. microrhynchus and S. holothuriae, Lee et al (2014) also discovered that the species concept of S. microrhyn-…”