Foxn1 is not essential for T-cell development in teleosts.

In mammals, T-cell development depends on the activity of the Foxn1 transcription factor in the thymic epithelium; mutations in the vertebrate-specific Foxn1 gene are associated with profound T-cell lymphopenia and fatal immunodeficiency. Here, we examined the extent of T-cell development in teleosts lacking a functional foxn1 gene. In zebrafish carrying a deleterious internal deletion of foxn1, reduced but robust lymphopoietic activity is maintained in the mutant thymus. Moreover, pseudogenization or loss of foxn1 in the genomes of deep-sea anglerfishes is independent of the presence or absence of the canonical signatures of the T-cell lineage. Thus, in contrast to the situation in mammals, the teleost thymus can support foxn1-independent lymphopoiesis, most likely through the activity of the Foxn4, an ancient metazoan paralog of Foxn1. Our results imply that during the early stages of vertebrate evolution, genetic control of thymopoiesis was functionally redundant and thus robust; in mammals, the genetic network was reorganized to become uniquely dependent on the FOXN1 transcription factor.

New species of the eel genera Dysomma and Dysommina from Vietnam, South China Sea (Anguilliformes: Synaphobranchidae).

Two new cutthroat eel species are described from Vietnam. Dysomma intermedium sp. nov. has a relatively long trunk, being about half of head length and anal-fin origin more than twice pectoral-fin length behind the pectoral-fin tip; pectoral fin well developed; dorsal-fin origin over or slightly in front of base of pectoral fin; two intermaxillary teeth; four or five compound teeth on ethmovomer; single row of seven or eight teeth on lower jaw; total lateral-line pores 70-76; and 21 pre-anal and 118-124 total vertebrae. Dysommina brevis sp. nov. differs from congeners by having a trunk shorter than head length, its length 11.1%-11.8% TL; a short pre-anal length 24.6%-25.6% TL, eye diameter 11.8%-12.3% head length; three large and one or two small teeth on ethmovomer; and fewer teeth on the upper and lower jaws. In addition, a specimen representing the first record of Dysommina orientalis in Vietnamese water is documented.

Hoplostethus roseus, a new roughy fish from the western Pacific based on morphology and DNA barcoding (family Trachichthyidae).

A new species of the roughy fish genus Hoplostethus is described from 11 types and a non-type specimen collected from Taiwanese waters. It can be distinguished from its congeners by a combination of characters: pectoral-fin rays 14-17 (modally 15-16); pyloric caeca 65-84; total gill rakers 19-20; predorsal scales 18-22; oral cavity, branchial chamber, top and underside of tongue, and peritoneum uniformly black; distal margin of membrane between dorsal-fin spines black; caudal fin without a black margin; caudal-fin base brownish. Comparisons of the new species with similar species are provided. DNA barcoding supports the monophyly of the new species, which appears to be closely related to Hoplostethus japonicus [average cytochrome c oxidase subunit I Kimura-2-parameter (COI K2P) distance of 4.1%].

A new Congrid eel, Rhynchoconger smithi sp. nov. (Anguilliformes: Congridae), from the Bay of Bengal, India.

A new Conger eel species is described based on four specimens collected from Petuaghat fishing harbour, West Bengal, India. The combination of morphological characters and molecular data are discordant with the seven congeners currently recognized. Rhynchoconger smithi sp. nov. can be distinguished by having head smaller than trunk; pre-anal length more than three times in total length; a small eye, diameter 2.0-2.2 in snout length; rictus ending at a vertical through posterior margin of pupil; ethmovomerine teeth patch small, with 58-74 blunt teeth arranged in seven to eight irregular rows; vomerine teeth patch small, with 18-28 granular teeth arranged in four to six irregular rows, distinctly separated by narrow spaces from the ethmovomerine and maxillary teeth; three supraorbital pores and one supra-temporal pore; and 159+ to 164 total vertebrae. Moreover, R. smithi differs significantly from four congeners, R. nitens, R. flavus, R. ectenurus and R. gracilior, with Kimura two-parameter (K2P) distances 14.6%-20.3%.

Description of a new perchlet, Chelidoperca formosa, from southwestern Taiwan (Peciformes: Serranidae).

A new perchlet species is described on the basis of four specimens collected from southwestern Taiwan. It is similar to congeners with relatively few lateral-line scales (35-38) and can be distinguished by having third to sixth dorsal-fin spines notably long; eighth and ninth dorsal-fin spines notably short; developed gill rakers 1 + 7-8; scale rows between lateral line and sixth dorsal-fin spine 4 (the dorsalmost half-sized); tip of upper corner of caudal fin reddish; four reddish bands midlaterally on body with groups of melanophores in these bands. DNA barcoding analysis reveals the new species is a distinct lineage and closest to Chelidoperca microdon. The average interspecific genetic distance calculated by the K2P model is 15.4%, whereas the mean distance from the new species to C. microdon is 18.3%. The inferred phylogenetic tree supports monophyly of Chelidoperca. Including the new species, six nominal species of Chelidoperca are recognized in Taiwanese waters.

Etelis boweni sp. nov., a new cryptic deepwater eteline snapper from the Indo-Pacific (Perciformes: Lutjanidae).

A new species of Etelis is described based on 16 specimens collected from the Red Sea and Western Australia, with confirmed genetic records throughout the Indo-West Pacific. It is similar to and was often misidentified as Etelis carbunculus Cuvier, with both species sharing the diagnostic character of low number of developed gill rakers. Nonetheless, the two species are genetically divergent and differ morphologically in adult body length; proportions of eye, snout, cheek and caudal fin; shape of head, opercular spine and sagittal otolith; and coloration of the tip of the upper caudal fin. Etelis boweni has a wide Indo-west Pacific distribution that largely overlaps with E. carbunculus, and the two species are often caught on the same fishing line.

Examining evolutionary relationships and shifts in depth preferences in batfishes (Lophiiformes: Ogcocephalidae).

Batfishes (Ogcocephalidae) are an understudied, group of marine anglerfishes that are dorsoventrally flattened and have an illicium and esca (terminal lure) used to attract prey. The family contains 10 genera and 75 recognized species from nearly all tropical and subtropical seas. Relationships among these taxa, as well as the position of Ogcocephalidae within Lophiiformes, remain poorly understood with previous studies showing conflicting, and poorly resolved results. The timing of divergence and depth of origination in the water column have also not been explored in any detail. In this study a concatenated nuclear (three genes) and mitochondrial (two genes) dataset was constructed across several anglerfish families to elucidate phylogenetic relationships among all ten batfish genera, to clarify the placement of Ogcocephaloidei within Lophiiformes, and to estimate divergence times using fossil calibrations. An ancestral state reconstruction was also conducted to examine the history of shifts in preferred habitat depths within batfishes. Phylogenetic analyses supported monophyly of each sub-order within Lophiiformes and placed Ogcocephaloidei as the sister group to Antennarioidei. Batfish genera were divided into an Eastern Pacific/Western Atlantic clade and an Indo-Pacific clade; Halieutaea was recovered as the sister group to all other batfishes. Based on divergence time estimations and ancestral state reconstructions of preferred depth, Ogcocephalidae is Eocene in age and originated on the lower continental shelf/upper continental slope (disphotic zone).

Does counting species count as taxonomy? On misrepresenting systematics, yet again.

Recent commentary by Costello and collaborators on the current state of the global taxonomic enterprise attempts to demonstrate that taxonomy is not in decline as feared by taxonomists, but rather is increasing by virtue of the rate at which new species are formally named. Having supported their views with data that clearly indicate as much, Costello et al. make recommendations to increase the rate of new species descriptions even more. However, their views appear to rely on the perception of species as static and numerically if not historically equivalent entities whose value lie in their roles as "metrics". As such, their one-dimensional portrayal of the discipline, as concerned solely with the creation of new species names, fails to take into account both the conceptual and epistemological foundations of systematics. We refute the end-user view that taxonomy is on the rise simply because more new species are being described compared with earlier decades, and that, by implication, taxonomic practice is a formality whose pace can be streamlined without considerable resources, intellectual or otherwise. Rather, we defend the opposite viewpoint that professional taxonomy is in decline relative to the immediacy of the extinction crisis, and that this decline threatens not just the empirical science of phylogenetic systematics, but also the foundations of comparative biology on which other fields rely. The allocation of space in top-ranked journals to propagate views such as those of Costello et al. lends superficial credence to the unsupportive mindset of many of those in charge of the institutional fate of taxonomy. We emphasize that taxonomy and the description of new species are dependent upon, and only make sense in light of, empirically based classifications that reflect evolutionary history; homology assessments are at the centre of these endeavours, such that the biological sciences cannot afford to have professional taxonomists sacrifice the comparative and historical depth of their hypotheses in order to accelerate new species descriptions.

Rediscovery of Lophiodes triradiatus (Lloyd, 1909), a senior synonym of L. infrabrunneus Smith and Radcliffe (Lophiiformes: Lophiidae).

Examination of the holotype and three recently collected additional specimens from the Indian Ocean has revealed that Lophius triradiatus Lloyd, 1909 (now under Lophiodes)  is a valid species and a senior synonym of Lophiodes infrabrunneus Smith & Radcliffe, 1912 and Lophiodes abdituspinus Ni, Wu & Li, 1990. A detailed description of the additional specimens is provided.

A new species of the sandperch genus Parapercis from the western Indian Ocean (Perciformes: Pinguipedidae).

Parapercis albiventer sp. nov., a new species of sandperch is described based on 12 specimens collected from the western Indian Ocean. It can be distinguished from congeners by having a bright white ventral surface, without color markings on lower fourth of body; dorsal surface of head and body densely covered by small brown spots; a row of 10 faint reddish blotches on a paler background, along body axis; row of 10 deep reddish blotches, the lower part of each blotch with a solid black bar ventrally, below mid-lateral body axis; and combination of following characters: no palatine teeth; snout long; eye small; interorbital space broad; dorsal-fin rays V, 21; anal-fin rays I, 17; pectoral-fin rays 16-17; pored lateral-line scales 55-59; predorsal scales 9 or 10; scales on transverse row 6/17-21; 3 pairs of canine teeth at front of lower jaw; and vertebrae 10 + 20 = 30.

Description of a large specimen of Paralepis elongata (Brauer, 1906) from Angola, southeastern Atlantic Ocean (Aulopiformes: Paralepididae).

The elongate barracudina, Paralepis elongata (Brauer, 1906), received limited attention in the past, with only a few individuals documented, mostly in publications focusing on the feeding habits of large predatory pelagic fishes. Furthermore, the taxonomic history of the species is complicated, with some earlier sources providing incorrect information that influenced subsequent works. As a result, the accurate distribution range of P. elongata remains uncertain. An adult male specimen of P. elongata, representing the largest known individual, is reported from off Angola, southeastern Atlantic. A detailed description is provided, and the literature records of the species are reviewed and discussed.

First case of a reversed Parabothus taiwanensis Amaoka & Shen, 1993 from Taiwan (Pleuronectiformes: Bothidae), with first evidence of situs inversus viscerum in bothid.

Background: Reversed condition is rarely found in most flatfishes in natural environment, except for some certain species. The mechanism controlling the reversals in flatfishes has been studied in some cultivated species, whereas some have only few cases for the entire family and remain unclear. Here, we report the first record of a dextral (reversed) specimen of Parabothus taiwanensis Amaoka & Shen, 1993 collected off southwestern Taiwan recently. It represents the second reversed case ever recorded in Bothidae. We aim to provide a detailed description of this dextral specimen and compared to the sinistral (normal) specimens collected from the vicinity. Methods: Specimens were fixed in 4% formaldehyde and transferred to 70% ethanol for preservation. Meristic and morphometric characters were examined for both dextral and sinistral specimens. Dissections were made on specimens to confirm the position of internal organs. Lastly, X-radiographs were taken to elucidate the osteological features. Results: As a result, no differences of both meristic and morphometric characters were observed between the dextral and sinistral specimens. Nevertheless, situs inversus viscerum is discovered in the dextral specimen for the first time in Bothidae and the sixth record within flatfishes.

DNA mini-barcoding reveals the mislabeling rate of canned cat food in Taiwan.

Background: Domestic cats are important companion animals in modern society that live closely with their owners. Mislabeling of pet food can not only harm pets but also cause issues in areas such as religious beliefs and natural resource management. Currently, the cat food market is booming. However, despite the risk that mislabeling poses to cats and humans, few studies have focused on species misrepresentation in cat food products. Methods: To address this issue, we used DNA barcoding, a highly effective identification methodology that can be applied to even highly processed products. We targeted a short segment (~85 basepairs) of the mitochondrial 16S rRNA (16S) gene as a barcode and employed Sanger or next generation sequencing (NGS) to inspect 138 canned cat food products in the Taiwanese market. Results: We discovered that the majority of mislabeling incidents were related to replacement of tuna with other species. Moreover, our metabarcoding revealed that numerous undeclared ingredients were present in all examined canned products. One product contained CITES Appendix II-listed shortfin mako shark (Isurus oxyrinchus). Overall, we uncovered a mislabeling rate of at least 28.99%. To verify cases of mislabeling, an official standardized list of vernacular names, along with the corresponding scientific species names, as well as a dependable barcoding reference sequence database are necessary.

Two new species of the batfish genus Malthopsis (Lophiiformes: Ogcocephalidae) from the Western Indian Ocean.

Two new species of the triangular batfishes, genus Malthopsis, are described from the western Indian Ocean. Both belong to a species group with minute prickles on the ventral surface. Malthopsis bradburyae n. sp. differs from its congeners by having the body covered by blunt, flat bucklers; subopercular buckler dull, without well-developed spines, its ventral surface covered by minute prickles and a few large bucklers anterior to the pelvic-fin base; rostrum moderately long, directed forward rather than upward; eye relatively small. Malthopsis austrafricana n. sp. differs from its congeners by having a long forward and horizontally directed rostrum; subopercular bucklers dull, without well-developed spines; ventral surface evenly covered by minute prickles and small bucklers; small black patches on dorsal surface; and a strong tail. Comments and a key to the Western Indian Ocean species of Malthopsis are provided.

Redescription of Parapercis punctata (Cuvier, 1829) and status of Neosillago Castelnau, 1875 and its type species Neosillago marmorata Castelnau, 1875 (Perciformes: Pinguipedidae).

The status of two doubtful fish species is reviewed. Percis punctata Cuvier, 1829 is confirmed to be a valid species of Parapercis Bleeker, 1863 and a senior synonym of Parapercis guezei Fourmanoir, 1966. A redescription of Parapercis punctata is provided, based on four specimens collected from the western Indian Ocean. Examination of the holotype of Neosillago marmorata Castelnau, 1875 revealed that Neosillago is a junior synonym of Parapercis and N. marmorata is a junior synonym of Parapercis nebulosa (Quoy & Gaimard, 1825).

Two new species of the coffinfish genus Chaunax (Lophiiformes: Chaunacidae) from the Indian Ocean.

Two new coffinfishes, Chaunax nebulosus n. sp. and Chaunax africanus n. sp., are described from the Indian Ocean. Both species belong to the C.fimbriatus-species group which is characterised by having filaments on the dorsal head and a complex color pattern on the dorsal surface. They are morphometrically and meristically conservative but differ in coloration. Chaunax nebulosus can be distinguished from its closest relatives by its dense covering of very small, irregular grayish green spots and having 5 small blackish markings on its dorsal surface. Chaunax africanus can be distinguished from other members in having a colour pattern of long narrow brown bars on the dorsal-fin base and head (forming a radiate pattern around the eye), and a complex white reticulate pattern (often double-lined) over the entire dorsal surface. Comments on species occurring in Indian Ocean and the status of members of C. fimbriatus-species group are also provided.

Redescription of Parapercis macrophthalma (Pietschmann, 1911) and description of a new species of Parapercis (Pisces: Pinguipedidae) from Taiwan.

Parapercis macrophthalina is confirmed as a valid species and redescribed on the basis of the holotype and other specimens collected from the type locality, Taiwan, and Japan. It is morphologically similar to P. muronis Tanaka, 1918, but differs in having five vertical transverse bars that extend well below the lateral line versus five oblique transverse bars, with the third to fifth bars ending on or above the lateral line. A new species is also described on the basis of a specimen collected from southwestern Taiwan. It is distinct in having numerous pores interconnected by canals on the head, forming 10 vertical or oblique rows on the cheek and opercular apparatus, predorsal scales extending to the level of the posterior margin of the eye, four dorsal-fin spines, six oblique bars laterally on the body, and a combination of other characters. A key to species of Parapercis with narrow transverse bars on the upper body is provided.

DNA sequences and morphological variation in Lophiodes iwamotoi Ho, Serét & Shao, 2011 based on new material from New Caledonia.

Iwamoto's anglerfish Lophiodes iwamotoi is recorded from New Caledonia for the first time. Study of molecular features further support the validity of the species. Moloecular sequence data from the cytochrome c oxidase subunit-I and Rhodopsin loci, along with morphological variation are provided, as well as information on its fresh coloration.

A review of the anglerfish genus Chaunax (Lophiiformes: Chaunacidae) from New Zealand and adjacent waters, with descriptions of four new species.

Species of the anglerfish genus Chaunax Lowe, 1846 from the New Zealand region are taxonomically reviewed with six species recognized and described: Chaunax penicillatus McCulloch; C. nudiventer Ho & Shao, a new record for New Zealand; and four species new to science. Chaunax flavomaculatus sp. nov. distinguished by having its skin covered with a mix of numerous bifurcated and simple spinules, large yellow spots on dorsal surface of fresh specimens, and brownish coloured escal cirri; Chaunax mulleus sp. nov. by having a uniformly pink body with a deep red colour on ventral surfaces of the outer pectoral-fin and pelvic-fin, and lower part of caudal fin; Chaunax reticulatus sp. nov. by having cirri on the dorsal surface of head, and a pale reticulate colour pattern on a greyish background dorsally; and Chaunax russatus sp. nov. by its very wide illicial trough that is usually as wide or wider than the diameter of the pupil, and uniformly deep red body colour with creamy white to fuzzy greyish spots or patches on its dorsal surface. A key to species recognized from the study area is given.

Revision of batfishes (Lophiiformes: Ogcocephalidae) of New Zealand and adjacent waters, with description of two new species of the genus Malthopsis.

Examination and taxonomic review of the batfishes collected from New Zealand and adjacent waters reveals five nominal species: Halieutopsis bathyoreos and Malthopsis mitrigera are recorded from New Zealand for the first time; the synonymy of Halieutaea maoria with H. stellata is confirmed, and two new species are described. Malthopsis asparata sp. nov. is unique in having stout principal bucklers with prominent spines. Malthopsis parva sp. nov. differs from congeners in having a naked abdomen, a short rostral spine directed upward, and all principal bucklers blunt.