Lobe Of Caudal Fin Research Articles

A new cyprinid species, Placocheilus dulongensis, from the upper Irrawaddy system in northwestern Yunnan, China

A new species of the cyprinid genus Placocheilus Wu 1977, is described from the Dulong River drainage (in the upper reach of the Irrawaddy River), northwestern Yunnan Province (China). Placocheilus dulongensis sp. nov. can be distinguished from the other three congeners, namely P. caudofasciatus, P. robustus and P. cryptonemus, by the following combination of characters: no semicircular black mark on the middle of each caudal fin lobe; no blackish band across the dorsal fin; one pair of rostral barbels and one pair of maxillary barbels; 39–40 perforated lateral line scales. Osteological characters, such as the shape of the second infraorbital, preoperculum, and the vertical plate of the urohyal were observed in a cleared and stained skeletal specimen. A simplified key to the genus Placocheilus is provided based on the comparisons among the four species.

A new goatfish, Upeneus seychellensis sp. nov. (Mullidae), from the Seychelles Bank, with remarks on Upeneus guttatus and a key to Western Indian Ocean Upeneus species

The mullid genus Upeneus is highly diverse, with a considerable number of new species found only recently. Based on 16 specimens of Upeneus collected at the southeastern edge of the Seychelles Bank, a large oceanic platform in the Western Indian Ocean, a new species, Upeneus seychellensis, is described. Comparisons with and among populations of the closely related U. guttatus are made. By integration of an extensive, comparative data set consisting of 50 morphometric and meristic and several colour characters obtained from 25 additional Upeneus species, an updated key for the 18 Western Indian Ocean species is provided. The new species can be distinguished from all other congeners of the japonicus-species group, a complex of species with seven dorsal-fin spines, by a combination of number of pectoral fin rays and gill rakers, body depth at anal fin origin, caudal peduncle depth, anal fin size, first dorsal-fin height and colour of the lower caudal-fin lobe. Co-occurring specimens of U. guttatus are considerably differentiated in morphology and colour from other Indian Ocean populations and this was also found for a single specimen from the Gulf of Suez. These results indicate isolation and the formation of local adaptation in more remote areas of the Indian Ocean, but the influence of phenotypic plasticity also needs to be considered.

A new species of the perciform fish genus Symphysanodon (Symphysanodontidae) from the Arabian Sea off the southwestern coast of India

Symphysanodon xanthopterygion, new species, reported herein from 15 specimens collected near Quilon, India, off the Kerala Coast in the southeastern Arabian Sea, becomes the twelfth described species in the genus. The following characters in combination distinguish S. xanthopterygion from its congeners: parapophyses present on first caudal vertebra, total number of gillrakers on first arch 38 to 42, tubed lateral-line scales 54 to 59, sum of lateral-line scales plus total number of gillrakers in individual specimens 94 to 101, head length 33 to 37% SL, head depth 18 to 21% SL, snout length 5 to 6% SL, body depth 24 to 27% SL, lower caudal-fin lobe bright yellow.

A new genus and two new species of Stevardiinae (Characiformes: Characidae) with a hypothesis on their relationships based on morphological and histological data

Lepidocharax, new genus, and Lepidocharax diamantina and L. burnsi new species from eastern Brazil are described herein. Lepidocharax is considered a monophyletic genus of the Stevardiinae and can be distinguished from the other members of this subfamily except Planaltina, Pseudocorynopoma, and Xenurobrycon by having the dorsal-fin origin vertically aligned with the anal-fin origin, vs. dorsal fin origin anterior or posterior to anal-fin origin. Additionally the new genus can be distinguished from those three genera by not having the scales extending over the ventral caudal-fin lobe modified to form the dorsal border of the pheromone pouch organ or to represent a pouch scale in sexually mature males. In this paper, we describe these two recently discovered species and the ultrastructure of their spermatozoa.

Description of a new goatfish species, <i>Upeneus randalli</i> n. sp. (Mullidae), from the Persian Gulf, with remarks and identification keys for the genus <i>Upeneus</i>

The number of species of the goatfish genus Upeneus from the western Indian Ocean has increased considerably due to recent taxonomic efforts. Here we describe a new species, Upeneus randalli n. sp., based on body and fin coloration and 50 morphometric and meristic characters of eight specimens from the Persian Gulf, and supported by comparative data from a taxonomic review of western Indian Ocean Upeneus species and additional material from collections. Upeneus randalli is distinguished from congeners by the combination of 8 dorsal-fin spines, 14 pectoral-fin rays, 23 to 25 gill rakers, 28 to 30 lateral-line scales, pectoral-fin width 22 to 26 times in SL, and red bars on both caudal-fin lobes. We provide two identification keys: one key is for distinguishing among four species groups and the morphologically unique U. filifer , accounting for all 28 species of the genus, and the other key is for the six closely related species of the “ U. tragula group” from the western Indian Ocean, including U. randalli n. sp. Since the colour patterns fade away soon after collection and can be completely lost during preservation, morphometric and meristic characters are important for correctly identifying U. randalli n. sp. and the closely related U. margarethae . The latter species shows considerable variation in body form in different areas of the western Indian Ocean. We discuss the significance of detailed comparative studies of caudal-fin colour patterns and body-form characters for obtaining a deeper understanding of inter- and intraspecific diversity among Upeneus .

Silurichthys ligneolus, a new catfish (Teleostei: Siluridae) from southern Borneo, Indonesia

Silurichthys ligneolus, a new species of silurid catfish, is described from blackwater habitats in southern Borneo. The new species can be distinguished from congeners in having a combination of: body depth at anus 9.1–11.0% SL, caudal peduncle depth 4.7–5.5% SL, eye diameter 6.7–9.8% HL, pelvic fins present, 44–45 anal-fin rays, 3–4 principal rays on the lower caudal-fin lobe, lower lobe of caudal fin indistinct, 46–48 vertebrae, one gill raker on the first branchial arch, and body uniformly brown. Based on the morphology of its caudal fin, S. ligneolus is hypothesized to be the sister taxon of S. sanguineus.

Two new trans-Andean species of Imparfinis Eigenmann & Norris, 1900 (Siluriformes: Heptapteridae) from Colombia

Two new species of Imparfinis are described from the trans-Andean region of Colombia. Imparfinis timana is diagnosed by having longer anal fin base (12.4-15.5% in SL), in combination with long adipose fin (24.6-31.3% in SL), 5-6 gill rakers on the first ceratobranchial, 42-43 vertebrae and additional measurements. Imparfinis usmai is distinguished by the combination of first ray of dorsal fin longest, but not projected as a long filament, long adipose fin (21.1-27.0% in SL), maxillary barbel exceeding pelvic-fin base, 39-40 vertebrae, upper caudal-fin lobe pointed and longer than lower lobe, lower lobe rounded, 7-8 gill rakers on the first ceratobranchial, as well as additional measurements. Imparfinis timana is only known from río Guarapas, a small tributary of the upper course of the río Magdalena. Imparfinis usmai is broadly distributed in the upper basin of ríos Cauca and Magdalena, and in the lower Patía river basin. The restricted distribution of I. nemacheir to trans-Andean drainages (Atrato, Magdalena, and Lago de Maracaibo) is also discussed.

A new species of Moenkhausia from the rio Amazonas and rio Orinoco basins (Characiformes: Characidae)

A new species of Moenkhausia is described from the rio Amazonas and rio Orinoco basins. The new species can be distinguished from congeners mainly by the combination of a conspicuous, relatively small and circular humeral spot, a black spot on the upper caudal-fin lobe, lower caudal-fin lobe without spot or a faint one, and middle caudal-fin rays hyaline or with dark tips. Mature males have a unique combination of two large-sized bony hooks on the anal-fin rays and tiny spines on the distal portion of all fins, which distinguishes the new species from any other species of Characidae.

Moenkhausia celibela: a new species from the Amazon basin, Brazil (Characiformes: Characidae)

A new species of Characidae, Moenkhausia celibela, is described from the Rio Amazonas at Santarém, Rio Maraú, several localities in the Rio Tapajós, Rio Curuá-Una, Rio Xingu and Rio Jari, all from the Amazon basin, Brazil. The new species is distinguished from its congeners, except species included in Géry's 1992 Moenkhausia lepidura group, by presenting a dark blotch on the upper caudal-fin lobe, and the lower lobe is hyaline or light grey. Moenkhausia celibela is distinguished from the species of the M. lepidura group by the absence of a humeral spot and the presence of a roughly triangular and dark spot at the caudal-fin base, extending posteriorly along the middle caudal-fin rays, and distinctly separate from the spot on the upper caudal-fin lobe.

A New Species of Rainbowfish (Teleostei: Melanotaenioidei: Bedotiidae) from the Makira Region of Northeastern Madagascar

Bedotia alveyi, a new species of Malagasy rainbowfish, is described from the lower reaches of the Antainambalana and Vohimaro rivers and their tributaries near the village of Maroansetra in the Makira Forest Protected Area, northeastern Madagascar. The new species is distinguished from congeners by the presence of a distinctive crescent-shaped to semicircular spangle on the posterior half of many opercular and flank scales, which creates iridescent golden (occasionally whitish to bluish) highlights. Additional unique pigmentation pattern features include a dark midlateral stripe interrupted by sparse lateral blotching and rust-red caudal-fin lobes. Bedotia alveyi is one of several new species that were collected during a brief expedition into the Makira Forest region in 2003. The Makira Forest was designated a Malagasy protected area in December of 2005.

On the occurrence of the Taiwan angel shark, Squatina formosa Shen & Ting, 1972 (Chondrichthyes, Squatinidae) from Japan

In the Pacific, most angel sharks display rather limited geographic distributions. Recent findings of three specimens of the Taiwan angel shark, Squatina formosa, from Tosa Bay, Kochi Prefecture, Japan enlarges the known geographic range of this species considerably. So far, this species only has been known from Taiwan. Other records might be considered misidentifications. The three specimens that form the focus of this study are from the central Tosa Bay (Province of Kochi) in SE Japan. They were collected with otter trawls in ca. 200 m depth in May and June 2008. Although these specimens differ slightly from the holotype from Taiwan in some features, their identification as belonging to Squatina formosa is well supported by the colour pattern and a suite of morphological characters such as shape and meristics of the upper lip arch, the shape of the caudal fin lobe and the shape and size of the pectoral, pelvic and dorsal fins. Additionally, the taxonomic identification is strongly supported by molecular and data by comparison with a specimen from Taiwan and previously published data. The mtDNA difference between the Taiwanese and Japanese populations is 0.2 % and is most likely related to a descent from a postulated original population some 10,000 years ago. It is most likely that this species occurs from the small Batan Islands, along the Ryukyu Trench and the corresponding Ryukyu Islands from Taiwan north along the south-eastern mainland coast of Japan. This species seemingly occurs along the Kuroshio Current and is absent from cold-influenced waters (e.g. western Taiwan, China and Japan seas). The recent finding of this species in Tosa Bay most probably is due to range extension because of globally increasing sea water temperatures.

The blind catfish from the caves of Chapada Diamantina, Bahia, Brazil (Siluriformes: Heptapteridae): description, anatomy, phylogenetic relationships, natural history, and biogeography

Rhamdiopsis krugi, a new troglobitic heptapterid catfish, is described from the caves of Chapada Diamantina, State of Bahia, northeastern Brazil. This species, although frequently cited in the scientific literature along the last seventeen years, remained undescribed largely due to its uncertain phylogenetic affinities. The generic assignment of R. krugi was clouded largely by its high number of unusual morphological features (some related to cave life), for instance: absence of eyes and body pigmentation; presence of a widely exposed pseudotympanum; posterior border of the anterior branch and anterior margin of the arborescent portion of the posterior branch of the transverse process of fourth vertebra joined; dorsal hypural plate commonly with seven rays; ventral caudal plate usually with six rays; dorsal and ventral caudal-fin lobes typically with six branched fin rays each; 38-39 vertebrae; anal fin with 14-17 rays; and lateral line very short. Rhamdiopsis krugi can be easily distinguished from its congeners, R. microcephala and R. moreirai, by its troglomorphic features and by the presence of a shorter lateral line, fewer vertebrae and anal-fin rays, pattern of branching of caudal-fin rays, and several attributes of skeletal system. The affinities of this new species are discussed in light of current phylogenetic knowledge of the family Heptapteridae. Incongruent derived characters do not allow selection of a particular hypothesis of sister group relationships among species of Rhamdiopsis. The occurrence of R. krugi in the rio Paraguaçu basin is possibly due to an event of hydrological capture from a section of the middle portion of the rio São Francisco basin, caused by tectonic events. The semi-arid region where R. krugi presently lives was probably covered by a wide forested area during a humid cycle in Quaternary. A summary of natural history and ecology data of R. krugi, as well as notes on its conservation, are provided. We also offer comments on the morphological plasticity of R. krugi.

Tachysurus spilotus, a new species of catfish from central Vietnam (Teleostei: Bagridae)

Tachysurus spilotus, a new species of catfish from central Vietnam, is described. It can be distinguished from congeners except T. argentivittatus, T. longispinalis, and T. virgatus in having a color pattern consisting of black longitudinal stripes on a pale body (vs. with a uniform-colored body with pale patches or transverse bands on a dark body, or with dark rectangular patches on a pale body). It differs from both T. argentivittatus and T. virgatus in snout shape and having gently convex (vs. straight) posterior edges of the caudal-fin lobes; and from T. longispinalis in having a shorter dorsalfin spine (ca. 27% SL vs. 15.1–19.0) and maxillary barbels (shorter, vs. longer than head). Tachysurus mica is shown here to be conspecific with—and a junior synonym of—T. argentivittatus.

Threatened fishes of the world: Cyprinus pellegrini pellegrini Tchang, 1933 (Cyprinidae)

Common name: Boshi carp (or Barbless carp). Conservation status: Listed as a Grade II State Protected Species in China; listed as vulnerable species in China Red Data Book of Endangered Animal— Pieces (Yue and Chen 1998). Identification: Body elongate; head large and broad; mouth large and terminal; eyes on upper half of head; barbels absent or with a pair of papilla at corners of mouth; scales rather large. Lateral line scales 34–37. Dorsal fin grayish dark, paired and caudal fins light yellow; lower lobe of caudal fin red (Yue and Chen 1998). Illustration: Xianwen (1982). Distribution: Endemic to China, in plateau lakes, Xingyun Lake and Qilu Lake of the Nanpanjiang River system, Yunnan province (Li et al. 1995). Habit and ecology: Lives in upper and middle layers of the deep parts of lakes in calm water (Yue and Chen 1998). Filter-feeder, feeding mainly on zooplankton, but its feeding apparatus is less developed and less powerful (filters less water) than those of bighead and silver carp (Cao 1992). It is highly sensitive to low temperatures (Sun and Liang 2004). Reproduction: Spawning period from April to September, peak in May and June. Batch spawning, eggs adhere to hydrophytes (Yue and Chen 1998) in shallow water where their larvae grow (Jia et al. 2008). Its major population is located in Jiangchuan Hatchery now (Jia et al. 2008). Fecundity can reach up to 130,000 in 3 to 4 year old females (Yue and Chen 1998). Threats: Wild populations have declined dramatically in recent decades from environmental fluctuations; slow growth rate; habitat destruction and loss of spawning grounds by decreasing of hydrophytes because of declining water levels; overfishing; and especially the invasion of exotic species (Jia et al. 2008). The proportion of barbless carp in the total fish yield declined to 20% in the 1960s, to 10% in the early 1970s, and now to less than 1% since the 1980s (Huang 1997). Conservation action: Transplanting, domestication and artificial reproduction have been carried out in Jiangchuan County and Yuanjiang County of Yunnan province (Yue and Chen 1998). Conservation activities were conducted in Heilongjiang Fishery Institute of CAFS Environ Biol Fish (2009) 86:485–486 DOI 10.1007/s10641-009-9558-4

Astyanax ajuricaba: a new species from the Amazon basin in Brazil (Characiformes: Characidae)

A new Astyanax species is described from several localities in the rio Negro, rio Solimões and lower rio Tapajós basins, Amazon basin, Brazil. The new species is distinguished from all remaining characids by its unique color pattern consisting of the combination of presence of a conspicuous, narrow dark midlateral stripe, a well-developed vertically-elongated dark humeral spot, and upper caudal-fin lobe and middle caudal-fin rays dark, with a rounded clear ocellated spot present at anterior third of caudal-fin lobe.

A new Tatia (Ostariophysi: Siluriformes: Auchenipteridae) from the rio Iguaçu basin, Paraná State, Brazil

A new species of Tatia is described from the lower rio Iguaçu basin, Paraná State, Brazil. The new species is distinguishable from congeners by having large, irregular pale blotches over dark brown base coloration, absent longitudinal stripe, caudal fin with round to striate dark brown spots over light base in adults or entirely dark in juveniles, and by having a long humeral process. Sexual dimorphism of the new species is marked by differences among genital and urinary apertures, size proportions between upper and lower lobe of caudal fin, and size, width and presence of antrorse and retrorse spines on anal-fin rays.

Threatened fishes of the world: Cyprinus qionghaiensis Liu 1981 (Cyprinidae)

Common name: Qionghai carp. Conservation status: Endangered, China Species Red List (Wang and Xie 2004). Identification: Body length 172–228 mm. Body laterally compressed. Head large (length 33.3% of SL), its length approximately equal to body depth. Mouth large and terminal, with a pair of short barbells at corners; lips thin; eyes large (diameter 17.2% of HL). Base of dorsal fin comparatively long (31.3% of SL), origin of dorsal fin opposite to that of pelvic fin, outer edge of it markedly concave; tips of pectoral fin reach or approach origin of pelvic fins; pelvic fins inserted under anterior second branched rays of dorsal fin; anal fin inserted under posterior third or fourth branched rays of dorsal fin; caudal fin deeply forked. Last simple rays of dorsal and anal fins spined and serrated on hind margins. Body color green yellow on back, yellow-white on abdomen, golden luster on sides; orange on lower lobe of caudal fin (Liu 1981; Ding 1994; Yue 2000). Distribution: Endemic, only distributed in the Qionghai Lake of Sichuan Province (Ding 1994). Abundance: Commercial fish before 1965, but less than 5% of the total Cyprinidae fish production (Liu et al. 1988); almost extinct since 1990s (Peng 2007). Habitat and ecology: Inhabits bottom of the lake with clear water. Mainly feeds on plankton, hydrophytes, benthos and organic debris. Reproduction: Breeding habits similar to Cyprinus carpio Linnaeus; sticky eggs laid on aquatic plants in April and May. Threats: Ecological niche competition with stocked fish since 1965. Egg predation by introduced fishes. Water pollution from urbanized area near lake and increasing boat traffic for tourism in recent decade. Destructive fishing and over-fishing. Conservation action: Listed as endangered and protected in Sichuan Province. Conservation recommendations: Habitat protection, pollution control, and fishing restriction. Investigate the wild population, and initiate artificial propagation to restock the lake. Environ Biol Fish (2009) 85:49–50 DOI 10.1007/s10641-009-9459-6

Revision der neotypischen Gattung Metynnis COPE, 1878. II. Beschreibung zweier neuer Arten und zum Status von Metynnis goeldii EIGENMANN, 1903 (Teleostei: Characiformes: Serrasalmidae)

Metynnis longipinnis sp. n. – a new species of Silverdollar from the río Casiquiare drainage in Venezuela is described. The new species is closely related to Metynnis hypsauchen (MÜLLER & TROSCHEL, 1844) according to its features (1) high number of gill-rakers, (2) long adipose fin, (3) deep body, (4) short head and (5) long occipitale and is clearly defined because of (1) the high number of serrae (36–37 vs. 27–32 of M. hypsauchen), (2) the small scales (91–93 vs. about 75–83), (3) uniformly silver colouration and (4) the extremely elongated dorsal fin and anal fin. From Metynnis altidorsalis AHL, 1924 the new species is clearly differentiated by its (1) number of gill-rakers (30–33 vs. 20–25 for M. altidorsalis), (2) the number of branched anal rays (37–40 vs. 32–37 for M. altidorsalis), (3) the number of serrae (36–37 vs. 29–35 for M. altidorsalis) and (4) the length of the occipitale (18.94–20.78 % SL vs. 11.7–15.6 for M. altidorsalis). Further on M. longipinnis sp. n. has a longer adipose fin (20.00–20.78 % SL vs. 11.8–16.2 for M. altidorsalis) and an elongation of the rays of dorsal and anal fin (vs. not elongated for M. altidorsalis). M. luna COPE, 1878, M. orinocensis (STEINDACHNER, 1908) and M. guaporensis EIGENMANN, 1915 are differentiated by its higher number of gill-rakers and lager head length. M. lippincottianus (COPE, 1870) has a completely different colouration. Metynnis polystictus sp. n. – a new species of Silverdollar from the río Xingu in Brazil is described. The new species is closely related to Metynnis anisurus AHL, 1924, which is considered as valid. M. polystictus sp. n. is clearly differentiated from M. anisurus by its (1) colouration (body without spots in M. anisurus vs. two different kinds of spots in M. polystictus sp. n.) and (2) the enlarged lower lobe of caudal fin (developed in M. anisurus vs. absent in M. polystictus sp. n.). The Synonymy of Metynnis goeldii EIGENMANN, 1903 with Metynnis lippincottinianus (COPE, 1870) could be confi rmed, because of the rediscovery of a syntype of Metynnis goeldii EIGENMANN, 1903 in the collection of the California Academy of Sciences (San Francisco).

On a new species of the genus Moenkhausia Eigenmann (Ostariophysi: Characidae)

A new species of the genus Moenkhausia is described from the middle portions of the Rio Tocantins and tentatively from the Rio Apure in Venezuela, Rio Orinoco drainage. It is diagnosed by the presence of a dark spot in the half proximal length of the upper caudal-fin lobe, and by the presence of a large, irregularly shaped humeral spot located above the sixth to ninth perforated lateral line scale which is more posteriorly positioned along the body side in relation to other members of the genus. The distribution pattern of the new species is discussed.

Knodus shinahota (Characiformes: Characidae) a new species from the río Shinahota, río Chapare basin (Mamoré system), Bolivia

Knodus shinahota, new species, is described from río Shinahota, a tributary of the upper rio Mamoré basin, Província de Tiraque, Cochabamba State, Bolivia. The new species can be distinguished from all congeners except K. chapadae and K. geryi by having six rows of scales between the lateral line and the dorsal-fin origin (vs 4 or 5 rows of scales in the other species). Knodus shinahota differs from K. chapadae by possessing more rows of scales between the lateral line and the pelvic-fin origin (5 vs 3½ or 4, respectively) and more lateral line scales (38-41 vs 36-38, respectively). It differs from K. geryi by possessing more rows of scales between the lateral-line and the pelvic-fin origin (5 vs 4, respectively); fewer branched anal-fin rays (17-20 vs 15-17, respectively), and by lacking the two symmetric, large, dark, blotches on the basal portions of the caudal-fin lobes that characterize K. geryi.