Rhyacoschistura larreci, a new genus and species of loach from Laos and redescription of R. suber (Teleostei: Nemacheilidae)

Zootaxa ◽  
2019 ◽  
Vol 4612 (2) ◽  
pp. 151
Author(s):  
MAURICE KOTTELAT

Rhyacoschistura, new genus, belongs to a group of genera (Physoschistura, Mustura, Pteronemacheilus, Petruichthys) characterised by the modified branched pectoral-fin rays of males, with a very thick first ray, usually without membranes between some of the branches and/or rays, and anterior rays and/or membranes covered by small tubercles at maturity. Rhyacoschistura is distinguished from them by the combination of: presence of a suborbital flap; emarginate caudal fin; lower lip with a wide median interruption and connected to isthmus by a frenum; body depth about equal from behind head to caudal-fin base. Rhyacoschistura larreci, new species, is described from the Mekong drainage in Xayaburi Province, Laos. It is distinguished by details of the morphology of the pelvic fin, and its colour pattern (flank with numerous narrow slanted bars, very irregularly organised and shaped, more or less connected, or sometimes covering the whole flank). Schistura suber, from Nam Ngum watershed, is redescribed on the basis of adults and placed in Rhyacoschistura.  

Zootaxa ◽  
2012 ◽  
Vol 3586 (1) ◽  
pp. 329 ◽  
Author(s):  
ZACHARY S. RANDALL ◽  
LAWRENCE M. PAGE

The genus Homalopteroides Fowler 1905 is resurrected and distinguished from the genus Homaloptera van Hasselt 1823based on a combination of characters including a unique mouth morphology, dorsal-fin origin over pelvic fin,≤60 lateral-line scales, and≤30 predorsal scales. Species included in Homalopteroides are H. wassinkii (Bleeker 1853), H. modestus(Vinciguerra 1890), H. rupicola (Prashad & Mukerji 1929), H. smithi (Hora 1932), H. stephensoni (Hora 1932), H. weberi(Hora 1932), H. tweediei (Herre 1940), H. indochinensis (Silas 1953), H. nebulosus (Alfred 1969), H. yuwonoi (Kottelat1998), and possibly H. manipurensis (Arunkumar 1999). Homalopteroides modestus (Vinciguerra 1890) is a poorlyknown species that was originally described from the Meekalan and Meetan rivers of southern Myanmar. It occurs in theSalween, Mae Khlong, and Tenasserim basins, and can be distinguished from all other species of Homalopteroides by thecombination of caudal-fin pattern (black proximal and distal bars, median blotch), 15 pectoral-fin rays, pectoral-fin lengthgreater than head length, 5½–6½ scales above and 5–6 scales below the lateral line (to the pelvic fin), 39–44 total lateral-line pores, no axillary pelvic-fin lobe, pelvic fin not reaching anus, orbital length less than interorbital width in adult, and maxillary barbel reaching to or slightly past the anterior orbital rim.


Zootaxa ◽  
2009 ◽  
Vol 1977 (1) ◽  
pp. 39-48
Author(s):  
HEOK HEE NG

Parakysis hystriculus, new species, is described from the Lalang River drainage in southern Sumatra. It can be distinguished from congeners in having a combination of branched pelvic-fin rays with anterior branch always shorter than posterior branch, lateral edges of head evenly sloping in dorsal view, anteriormost pair of accessory inner mandibular barbels longer than distance separating bases of left and right barbel, outer mandibular barbel with one accessory barbel, mandibular laterosensory pore between bases of inner and outer mandibular barbels present, margin of lower lip with medial concavity, anal fin rounded, caudal fin with narrow lobes having evenly-tapering posteromedial margins and 10 branched rays without secondary branches.


Zootaxa ◽  
2019 ◽  
Vol 4691 (5) ◽  
pp. 444-460 ◽  
Author(s):  
WILLIAM T. WHITE ◽  
FAHMI FAHMI ◽  
SIMON WEIGMANN

A new genus and species of catshark is described based on a single specimen collected off Ambon in the Maluku Islands of eastern Indonesia. Akheilos suwartanai belongs to the subfamily Schroederichthyinae which differs from the other catsharks in a combination of: similar sized dorsal fins, supraorbital crests present, pseudosiphon present on claspers, broad subocular ridges under eyes, posterior nasal flaps present, tips of rostral cartilage fused into a rostral node. It represents the first record of this subfamily outside of the Americas. Akheilos differs from the other genus in the subfamily, Schroederichthys in a combination of: clasper groove not fused dorsally, ventral lobe of caudal fin produced, more intestinal valve turns, anal fin slightly larger than second dorsal fin, and in colour pattern. 


Zootaxa ◽  
2019 ◽  
Vol 4603 (2) ◽  
pp. 377 ◽  
Author(s):  
RALF BRITZ ◽  
V.K. ANOOP ◽  
NEELESH DAHANUKAR ◽  
RAJEEV RAGHAVAN

Aenigmachanna gollum, new genus and species, is described from Kerala, South India. It is the first subterranean species of the family Channidae. It has numerous derived and unique characters, separating it from both the Asian Channa Scopoli and the African Parachanna Teugels & Daget. Uniquely among channids, A. gollum has a very slender (maximum body depth only 11.1–11.3% SL), eel-like body (head length 20.8–21.6% SL), large mouth (jaw length 60.4–61.1 % HL), 43–44 anal-fin rays, 83–85 scales in a lateral series, an unusual colour pattern and it lacks pored lateral-line scales on the body and body buoyancy. In addition, it is distinguished by its DNA barcode sequence, which is 15.8–24.2% divergent from other species of the family Channidae. Morphological modifications usually associated with a subterranean life, such as reduction of eyes and enhancement of non-visual senses (taste, smell, mechanosensory systems) are absent in A. gollum. However, it shares with subterranean fishes a slight reduction of its pigmentation in comparison to epigean channids.


2005 ◽  
Vol 3 (4) ◽  
pp. 455-464 ◽  
Author(s):  
Aléssio Datovo ◽  
Maria Isabel Landim

Ituglanis macunaima, new species, is described from the rio Araguaia basin, Mato Grosso, Brazil. It is distinguished from its congeners by the following combination of characters: posterior fontanel absent; pectoral-fin rays usually i,4; pelvic-fin rays usually i,4; branched caudal-fin rays usually 5,5; mottled color pattern formed by irregular to roundish dark brown spots on whitish background; reduced supraorbital canal with pores s1 and s2 lacking; reduced infraorbital canal with pores i1 and i3 lacking; 2-3 pleural ribs; and 35-38 vertebrae. A detailed description and illustrations of the skeleton of I. macunaima are also provided. Comparisons with other trichomycterids are presented, and several reductive traits of I. macunaima are discussed. Some comments are made about the systematics and phylogeny of the genus.


Zootaxa ◽  
2008 ◽  
Vol 1852 (1) ◽  
pp. 65 ◽  
Author(s):  
MICHAEL MAIA MINCARONE ◽  
M. ERIC ANDERSON

The eelpout Leucogrammolycus brychios gen. et sp. nov., is described from nine specimens, five males (92–198 mm SL) and four females (99–205 mm SL), collected from off Rio de Janeiro state, southeastern Brazil, at depths from 536 to 632 m. It is mainly characterized by the following combination of characters: vertebrae 23–26 + 62–66 = 85–92; first anal-fin pterygiophore associated with first or second caudal vertebrae; scales absent; lateral line with mediolateral and ventral branches; upper lip broadly adnate to snout tip; gill slit not reaching ventrally to opposite lower end of pectoral-fin base; pelvic-fin rays 2; head pores relatively few, small, rounded; and whitish mid-body stripe forming a chevron on top of snout.


Zootaxa ◽  
2021 ◽  
Vol 5048 (2) ◽  
pp. 253-264
Author(s):  
KYOJI FUJIWARA ◽  
TOSHIYUKI SUZUKI ◽  
HIROYUKI MOTOMURA

Callogobius falx n. sp. (Gobiidae) is described on the basis of two specimens (14.4 and 23.1 mm in standard length: SL) from the Ryukyu Islands, southern Japan. The new species is characterized by the following combination of characters: dorsal-fin rays VI-I, 8 or 9; anal-fin rays I, 7; pectoral-fin rays 18 or 19; lateral scale rows 20–22; body depth moderate, neither particularly slender nor deep (depth at pelvic-fin origin 18.3–20.0% of SL); pelvic-fin base with frenum; caudal-fin length moderate, margin rounded; cephalic sensory-canal pores absent; interorbital papillae row separated, forming two rows (one row in 14.4 mm paratype); postorbital papillae row not continuous with upper cranial papillae row; preopercular and transverse opercular papillae rows connected, forming single transverse row; body with three oblique black bars, angled upwards anteriorly and continuous with black bars on dorsal fins, anteriormost bar extending from 1st dorsal fin to midline of body, posterior two bars extending from second dorsal fin to dorsal surface of body and caudal peduncle, respectively; pectoral fin white, upper half widely (ca. 1/2 length of rays) margined with black; caudal-fin base with narrow sickle-like bar.  


2008 ◽  
Vol 6 (4) ◽  
pp. 663-678 ◽  
Author(s):  
Cristina M. Bührnheim ◽  
Tiago P. Carvalho ◽  
Luiz R. Malabarba ◽  
Stanley H. Weitzman

Amazonspinther dalmata, a new miniature characid from the streams of rio Purus and rio Madeira, right bank tributaries of the rio Amazonas, is described as a new genus and species of the subfamily Cheirodontinae. The unique characters of the new genus and species are the three remarkable black blotches on the base of the dorsal, anal, and caudal fins, the anteriormost proximal radial of the anal fin with an anteriorly extended lamina entering the abdominal cavity, and the extremely elongate caudal peduncle. The reduced number of ventral procurrent caudal-fin rays (7-9), and the hemal spines of only posterior one, two, or sometimes three caudal vertebrae directly articulating with the ventral procurrent caudal-fin rays further diagnoses the new taxon from remaining genera of the tribe Cheirodontini. The results of a phylogenetic analysis strongly support a close relationship between A. dalmata and Spintherobolus in the tribe Cheirodontini on the basis of fifteen unambiguous synapomorphies. Ten of these characters, previously hypothesized as exclusive synapomorphies for Spintherobolus, were now also identified in Amazonspinther, such as the pattern of exposed neuromasts on the head, the presence of a second pseudotympanum anterior to the first pleural rib, and the nearly discoidal coracoid bone. A discussion about the phylogenetic position of the closely related fossil †Megacheirodon to Spintherobolus and Amazonspinther is also provided. Convergent characters shared between Amazonspinther and the characid Priocharax are discussed in relation to miniaturization. Biogeographical implications of the diversification of Amazonspinther, Spintherobolus, and Megacheirodon lineages are discussed.


Zootaxa ◽  
2017 ◽  
Vol 4338 (2) ◽  
pp. 333
Author(s):  
ANTHONY C. GILL ◽  
GERALD R. ALLEN ◽  
MARK V. ERDMANN

The Pseudochromis reticulatus complex is diagnosed to include species of Pseudochromis with the combination of a pointed caudal fin (rounded with middle rays produced), a reticulated colour pattern on the upper part of the body, dorsal-fin rays modally III,26, anal-fin rays modally III,15, and pectoral-fin rays modally 18. Members of the complex include P. reticulatus Gill & Woodland, P. pictus Gill & Randall, P. tonozukai Gill & Allen, P. jace Allen, Gill & Erdmann and P. stellatus new species. The last-named is herein described from six specimens from Batanta and Batu Hitam in the Raja Ampat Islands, West Papua, Indonesia. It is distinguished from other members of the complex in live coloration, and in having higher mean numbers of scales in lateral series and of anterior lateral-line scales (36–38 and 29–32, respectively), and a deeper body as measured from the dorsal-fin origin to pelvic-fin origin (31.8–33.5 % SL). 


Zootaxa ◽  
2017 ◽  
Vol 4269 (4) ◽  
pp. 559 ◽  
Author(s):  
RICHARD WINTERBOTTOM

Two new species of Trimma are described from Fiji. Trimma bathum n. sp. lacks scales on the cheeks, opercle and predorsal midline, has 18–19 unbranched pectoral fin rays, an unbranched 5th pelvic fin ray that is 40–56% the length of the 4th ray, 17–18 gill rakers on the outer surface of the first gill arch, a U-shaped interorbital and a narrow slit-like postorbital trench, a low, median fleshy ridge extending half-way towards the orbit from the origin of the first dorsal fin, and, when freshly collected, a pink head and body with most body scales having an orange-brown spot or short bar at their centres. The species is currently known only from off Suva Harbour, Viti Levu, Fiji. Trimma finistrinum n. sp. has a bony interorbital equal to the pupil diameter, a fully scaled nape of 12–14 scales, a second dorsal spine that may reach posteriorly to the middle of the second dorsal fin, the papillae in the longitudinal row immediately below the eye either single or with two papillae in a vertical row, unbranched pectoral fin rays, usually a branched fifth pelvic-fin ray that is about half length of the fourth ray, and a large diffuse dark blotch on the posterior part of the caudal peduncle. A colour pattern of a brownish body with most body scales having golden- to greenish-yellow (pale in preservative) centres is unique among species of the genus. The species is currently recorded only from off the north and east coasts of Viti Levu, Fiji.


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