Unbranched Ray Research Articles

Microlepidogaster dimorpha, a new species of Hypoptopomatinae (Siluriformes: Loricariidae) from the upper rio Paraná system

Microlepidogaster dimorpha, new species, is described from tributaries of rio Grande, upper rio Paraná system. Microlepidogaster dimorpha differs from M. perforatus and M. longicolla by having first dorsal-fin proximal radial attached to the neural spine of seventh vertebra, with posterior portion contacting also the eighth centrum (vs. first dorsal-fin proximal radial attached to the neural spine of eighth or ninth vertebra in M. perforatus, and to the neural spine of tenth or eleventh vertebra in M. longicolla); 29-30 vertebrae (vs. 31 in M. perforatus and 31-33 in M. longicolla); 18-21 mid-dorsal plates (vs. 9-13 in M. perforatus, and 13-17 in M. longicolla); deeper caudal peduncle (10.0-11.4% in SL vs. 7.7-8.5% in M. perforatus, and 5.4-7.3% in M. longicolla); greater distance between dorsal-fin origin and anal-fin insertion (19.4-23.8% in SL vs. 16.4-18.8% in M. perforatus, and 14.7-16.2% in M. longicolla); and nostril width markedly wider in males than in females (vs. approximately equivalent in size for both sexes, slightly wider in males than in females in M. perforatus, and equivalent in size for both sexes in M. longicolla). Microlepidogaster dimorpha also differs from M. perforatus by presence of the iris operculum (vs. absence); median plate series complete to caudal peduncle end (vs. median plate series truncated, with last two plates of dorsal and ventral series contacting in midline); greater head depth (43.4-53.1% vs. 40.7-42.3% in HL); greater orbital diameter (13.6-18.5% vs. 11.1-13.5% in HL); pelvic-fin first unbranched ray longer in males than in females (vs. equivalent in size in both sexes); and supraneural without paired anterior processes (vs. processes present). Additionally, M. dimorpha can be distinguished from M. longicolla by having anterior margin of snout with a paired rostral plate (vs. snout with small plates, naked in the anterior margin); by pectoral-fin axillary slit present, even in adult specimens (vs. pectoral-fin axillary slit present only in juvenile specimens); longer pectoral-fin unbranched ray (20.0-23.8% vs. 13.4-16.2% in SL in M. longicolla).

Description of a new species of sand-dwelling catfish of the genus Stenolicmus (Siluriformes; Trichomycteridae)

Stenolicmus ix, new species, is described from Igarapé Curuá, left tributary of the Rio Amazonas, Pará, Brazil. It can be distinguished from S. sarmientoi by the length of the nasal barbels that reach the base of the first opercular odontodes; length of the maxillary barbels that reach the posterior margin of the opercular odontode plate; seven well-developed opercular odontodes; seven well-developed interopercular odontodes; color pattern of the dorsal region of trunk composed of agglomerated chromatophores forming circular patches twice the diameter of the eye; proportionally large eyes, 11.8% HL; caudal peduncle tall, 11.6% SL, without dark bar at base of the caudal fin; length of the head proportionately larger, 17.9% SL; unbranched rays of caudal fin reaching distal margin of fin. Comparisons with other Sarcoglanidinae and Trichomycteridae are presented. Some comments on the systematics and phylogenetic relationships of the group are made.

Species of the Doumea chappuisi Complex (Siluriformes, Amphiliidae) with the Descriptions of New Species from the Upper Sanaga River and Nyong River Basins

Abstract The Doumea chappuisi complex within the catfish family Amphiliidae is diagnosed on the form of the dorsolateral and ventrolateral processes of the vertebrae along the posterior portion of the body. Three species are recognized in the complex: Doumea chappuisi of the West African coastal river basins in Guinea, Guinea-Bissau, Cote d'Ivoire, and Liberia; D. reidi, new species, described herein from a portion of the upper Sanaga River in Nigeria; and D. stilicauda, new species, described herein from the Nyong River basin in Cameroon. Members of the complex are distinguished from each other on the basis of the overall body form, the caudal-peduncle length, the predorsal length, the head length, the degree of development of the pelvic fin in larger specimens, the anterior extent of the exposed vertebral processes along the ventral surface of the body, and details of the pigmentation pattern of the unbranched rays of the pectoral and pelvic fins.

Eviota nigrispina, a New Goby from the Ryukyu Islands, Japan (Teleostei: Gobiidae)

A new species of goby, Eviota nigrispina, is described from the Ryukyu Islands Japan. The species belongs to cephalic sensory-pore pattern group 2 of Lachner and Karnella (1980), has an 8/7 dorsal/anal formula, unbranched pectoral-fin rays. It has a distinct black stripe running along the backbone in live or freshly caught fish, and strong black pigment along scale pockets on the ventral half of the sides when preserved.

Morphogenetic bases and parametric system of trichome evolution in plants of the genus Draba L.

Using quantitative morphological analysis of light microscopy data, the normal variation of trichome morphogenesis is studied in six whitlow grass species (Draba L.) and the morphological variation of adult trichomes in 11 species. The evolution consists in the transition from a radial morphogenesis pattern to bilateral and replacement of complex (branched) trichome rays with simple (unbranched) rays. A parametric system is constructed for classification of the ray morphology; this system includes two parameters-the ratio of the numbers of complex to simple rays, characterizing the probability of secondary branching of primary buds, and the number of primary buds, characterizing the probability of primary branching on the surface of the trichome cell. In this parametric space, all of the studied species fit well a third-order curve consisting of two ascending branches displaying a positive correlation between the primary and secondary branchings and a descending branch, located between them, where the primary and secondary branches are negatively correlated. The deduced evolutionary direction is almost independent of the size of the trichome cells and is explained exclusively by the mechanics of morphogenesis: acceleration in the development of the primary bud of the ray decreases the probability of its own branching and creates additional elastic extension of the cell surface, preventing other buds from branching. The morphogenesis itself appears to be a mechanically nonholonomic system, filtering in a selective manner the fluctuations of the same sign, which explains the directed pattern of its evolution. In the evolutionarily initial state, trichome ontogenesis is absent because its modules (primary buds) are formed by a mirror duplication. The ontogenesis commences when mirror symmetry in the formation of modules is lost and replaced with an axial pattern; thus, the change in the morphological type of buds is a direct consequence of the emergence of ontogenesis and its further evolution. Its main material is intraindividual variation, the only source of which is the mechanics of morphogenesis itself. It is found that morphological evolution can take place at an initially zero heritability and zero adaptive value of morphological differences.

Threatened fishes of the world: Capoeta antalyensis (Battalgil, 1943) (Cyprinidae)

Common name: Antalya barb (English), Antalya Saribaligi (Turkish). Conservation status: Vulnerable VU D2 (Crivelli 2006). Identification: D III/8–9, A III/5, P I/15–17, V I/7–8 and Ll. 50–56. Reachs 195 mm TL. Body elongated and fusiform. The mouth is ventral and like a half-moon, two pairs of barbels. Body covered by moderate scales. Last unbranched ray of the dorsal fin thickened, slightly emarginated and denticulated up to 2/3 of its length. Grey to blackish coloration on dorsal and sides, and silver-grey ventrally (Karaman 1969; Erk’akan and Kuru 1983). Distribution: The Antalya barb has a very restricted distribution. There are three populations, Aksu, Koprucay and Boga Streams (Kucuk and Ikiz 2004). Abundance: It is abundant in the Aksu, but is rare in the Koprucay and Boga (Kucuk and Guclu 2006). Habitat and ecology: This species prefers upper reaches, with high flow, clear and cold water, and inhabits shallow streams with sandy and pebbly bottom, being concurrently with Salmo trutta macrostigma (Kucuk and Ikiz 2004). Reproduction: Very few data are available. Breeding takes place from May to June (Kucuk and Ikiz 2004). Threats: C. antalyensis is threatened due to its limited distribution. Furthermore, river damming for hydroelectricity resulted in destruction of shallow water habitats and in the decline of their populations. Conservation action and recommendations: Besides the inclusion in the IUCN International Red List, no specific legal protection or conservation actions have yet been taken. In order to implement future management and protection programs, further research addressing the biology, ecology, genetic diversity and population status of the species is required. However, future conservation efforts should include the protection of the species natural habitats. Remarks: C. antalyensis is highly endemic with restricted distribution.

Sinocyclocheilus guilinensis, a new species from an endemic cavefish group (Cypriniformes: Cyprinidae) in China

The endemic Chinese cavefish genus Sinocyclocheilus possesses very rich species diversity. Specimens of this genus collected from Guilin, Guangxi, China, were originally described in an unpublished document in 1982. Later, they were recognized as Sinocyclocheilus jii. Comparison to the type specimens of S. jii leads to the conclusion that, though similar, they represent two different species. Herein we describe them as a new species, Sinocyclocheilus guilinensis sp. nov. It can be distinguished from all congeners by its possession of soft, unbranched dorsal ray without serrations, 19–20 (11–12) scale rows above (below) the lateral line, 34–36 circumpeduncular scales and 8–9 pre-dorsal vertebrae. Sinocyclocheilus guilinensis sp. nov. is most similar to S. jii. In addition to the scale count differences, a morphometrics-based principal component analysis (PCA) also supports designation of S. guilinensis and S. jii as two distinct species.

Reproductive morphology of Brittanichthys axelrodi (Teleostei: Characidae), a miniature inseminating fish from South America

Light and electron microscopy were used to investigate the morphology of reproductive characters in a characid fish, Brittanichthys axelrodi. Spermatozoa were found in ovaries of females, thereby confirming insemination in this species. Bony hooks can be found on the fourth unbranched ray and branched rays 1-4 of the anal fin and the unique sigmoidally-curved ray of the caudal fin in mature males. Testes have three distinct regions: an anterior spermatogenic region, an aspermatogenic middle region lined with a simple squamous epithelium and used for storage of mature spermatozoa, and a posterior region of coiled chambers lined with a high simple cuboidal epithelium. The most posterior region appears to be instrumental in the formation and storage of spermatozeugmata, unencapsulated sperm packets. Thus far, this tripartite testis morphology is unique among characids. The mature spermatozoon has an elongate nucleus ( approximately 5 microm in length). A striated rootlet originates at the anterior end of the distal centriole and continues to the anterior tip of the cell. The striated rootlet wraps around the entire ventral area of the anterior part of the nucleus and appears to continue around the anterior tip of the nucleus and down the dorsal side as electron-dense material. Several large, spherical mitochondria ( approximately 0.6 microm in diameter) with lamellar cristae overlap the posterior end of the nucleus and continue beyond together with the cytoplasmic collar that contains the flagellum which lacks axonemal fins. Each spermatozeugma is lanceolate in shape when sectioned mid-sagitally, with the core staining positively for mucopolysaccharides. In both sexes, the gonopore opens posterior to the anus, with the urinary pore having a separate opening posterior to the gonopore. Bands of skeletal muscle were found in the area of the male gonopore. These morphological features are likely linked to the reproductive mode of insemination, a trait that is so far as known, relatively rare among teleost fishes, but is proving increasingly frequent among certain groups of characid fishes.

Sinocyclocheilus donglanensis, a new cavefish (Teleostei: Cypriniformes) from Guangxi, China

Sinocyclocheilus donglanensis, a new cyprinid species from a subterranean river in Donglan County in the Guangxi Zhuang Autonomous Region of southern China, is described. It is distinguished from all congeners by the following combination of characteristics: a completely scaled body with well-developed eyes; a curved lateral line possessing 57–64 scales; pectoral fin not reaching pelvic fin origin and last unbranched ray of the dorsal fin clearly serrated along its posterior edge; 8–9 predorsal vertebrae; 8–9 gill rakers; joints of dentary-angulars not close to each other at the isthmus; and a slightly inferior mouth with the upper jaw (6.2–7.4% in standard length: SL) protruding slightly beyond the lower one (5.7–6.7% SL). Sinocyclocheilus donglanensis is sympatric with the peculiarly shaped, hunchbacked S. altishoulderus.

Threatened fishes of the world: Barbus haasi (Mertens 1925) (Cyprinidae)

barbel not reaching the rear edge of the eye. Last unbranched ray of the dorsal fin with small denticles. Anal fin is long and caudal peduncle is short and high. Body presents dark blotches. Part of caudal, anal and pelvic fins are red. Drawing by Rafael Miranda. Distribution: Most headwater streams of the Ebro River Basin and North Mediterranean rivers of the Iberian Peninsula. Abundance: Restricted to headwaters and occasionally in middle reaches of streams, scarce where present. Habitat and ecology: This benthonic species prefers upper reaches of rivers, with high flow and clear, cold waters. Barbus haasi occurs in rocky and vegetated areas and feeds on macroinvertebrates (mainly Chironomidae, Ephemeroptera and Trichoptera). Reproduction: The spawning period extends throughout April and June, related to periods of high stream flow. Fecundity ranges from 2000 to 7000 eggs per female. The males have an early maturity (one year) and grow more slowly than females. The females live for 8 years while the males only live for 7 years. The females have multiple spawning, releasing two to five egg batches depending on their size, such that largest females spawn more batches than the small ones (Aparicio & Sostoa 1998). Threats: The species is threatened by invasive alien fish species (mainly piscivores) and habitat loss due to water abstraction, construction of small dams, stream desiccation, etc. Anthropogenic water pollution is another important disturbance factor. This endemic species of the Iberian Peninsula is currently in rapid decline because the above noted impacts are intensified by the characteristic irregularity of the Mediterranean rivers. Conservation action: None. Conservation recommendations: Waste water and water pollution control and treatment. Correction of the impact of stream regulation by water releases to simulate natural flow patterns. Prevent alien fish species introductions and eradication of the existing alien species which impact on B. haasi. Habitat protection and control of invasive alien fish species are the main actions necessary to prevent the further decline of Barbus haasi. Remarks: There has been some controversy with regard to the systematic position of

Threatened Fishes of the World: Leuciscus lucumonis Bianco, 1983 (Cyprinidae)

Common name: Cavedano di ruscello (Italian), Brook chub (E). Conservation status: This Italian endemic species has undergone a progressive decline in its original range (Bianco & Taraborelli 1984, Bianco 1991, 1995, Mearelli et al. 1996, Bianco & Ketmaier 2001) since it was first described (Bianco 1983). Leucisus lucumonis is an important biogeographic indicator of the Tuscany-Latium district (Bianco & Ketamaier 2001). At present there are only about 10–12 isolated populations. According to the 2002 IUCN Red List of Threatened Species. www.redlist.org, downloaded on 14 August 2002, the status of this species (erroneously reported as L. lucumontis, Bianco 1983) was listed as at ‘Lower Risk’, (conservation dependent). Today L. lucumonis can be allocated to the endangered category for threatened species as it satisfies paragraph B and point 1 of the IUCN (1996) criterion ‘Severely fragmented distribution’. Identification and origins: The brook chub is a moderate sized species, which rarely reaches 200 mm TL and a maximum age of 5 years. Pharyngeal tooth formula 5.2-2-5. Dorsal fin origin placed behind the anterior origin of pelvics. Meristic counts: dorsal fin 3 unbranched rays and modally 7 branched rays, anal fin 3 unbranched rays and modally 8 branched rays, lateral line scales 40–42 (rarely over 43), 16 circumpeduncular scales. Ground colour of body yellowish, a pale golden iridescent longitudinal band is discernible on the middle part of the sides. Iris light with a brownish semilunar area in the upper half. All fins are greyish with some orange during the spawning season. Caudal fin uniformly greyish, without black tinged free margin as in the common chub Leuciscus cephalus (L.). L. lucumonis seems derived from L. cephalus as a result of vicarious events about 0.5 MYA. (Ketmaier et al. 1998). Drawing by Mariano Caminoli from a 132 mm SL specimen from Tiber River, Zoological Department of Naples University (Cat. N.: IZA 831). Distribution: Main rivers of the Tuscany–Latium district: Tiber R. with about 3–4 reproducing populations; Ombrone River with 3; Arno River probably 3–4, and Serchio River probably extirpated. Abundance: Scarce everywhere. Some moderately structured populations occur only in clean undisturbed brooks. Habitat and ecology: L. lucumonis is a primary, warm-water adapted, obligate riverine cyprinid fish. It lives mainly in brooks, occasionally found in main river courses. It lives together with young of the congeneric L. cephalus and other riverine Tuscany–Latium endemic species: these brooks represent relicts biotopes of biogenetic diversity of rheophilic endemic species of the Tuscany-Latium district (Bianco & Ketmaier 2001). Reproduction: Apparently from April till June. There are no accurate studies on its biology. Threats: The brook chub is very sensitive to pollution, habitat modification and competition with aliens. Its disappearance is mainly due to the introduction of Chondrostoma genei (Bonaparte 1839), a species endemic to northern Italy, heavily stocked in central Italy. This species can colonize small riverine biotopes. Conservation action: River restoration, eradication of introduced species, protection of small brooks, reintroduction of stocks in restored habitats and habitat protection. Conservation recommendation: Avoid any kind of alien introductions especially stocking with ‘white fishes’ (a mixture of mostly unidentified cyprinid and other species of uncertain origins), which often include riverine species, which can compete with L. lucumonis.

Description and familial allocation of the African fluvial genus Teleogramma to the Cichlidae

The external morphology, osteology, and myology of the African fluvial genus Teleogramma are described, and its familial allocation is discussed. Teleogramma is included in the family Cichlidae by loss of a major structural association between adductor mandibulae sections 2 and w, and by having an insertion of a large ventral division of adductor mandibulae section 2 onto the anguloarticular, expanded head of the fourth epibranchial, transversus dorsalis subdivided into four parts, functionally decoupled premaxillae and maxillae, the stomach's extendible blind pouch, the left-hand exit to the anterior intestine, the first intestinal loop at the left side, two epurals, seven branched rays on each upper and lower caudal fin lobe, free first uroneural from a united element of first preural and ural vertebra, and third preural vertebra fused with its haemal spine. Seven synapomorphies supporting the monophyly of Teleogramma are indicated, including the absence of or very low supraoccipital crest, the presence of a nostril tube, nonextended supraoccipital anteriorly, absence of extensive cartilaginous cap on the anterior border of the second epibranchial, presence of a beaklike projection on the cleithrum, caudal branched slip of epaxialis that inserts onto the upper two or three branched rays on the upper lobe of the caudal fin, and flexor dorsalis superior, which inserts onto the lower four unbranched rays on the upper lobe of the caudal fin.

Two New Eviota Species from the Hawaiian Islands (Teleostei: Gobiidae)

Eviota epiphanes has been the only Eviota species known from the Hawaiian Islands, but two additional undescribed species have been discovered. Eviota susanae n. sp. is described from shallow, sheltered habitats within Kaneohe Bay, Oahu, and Eviota rubra n. sp. from deeper spur and groove or ledge habitats outside Kaneohe Bay. Both species share a possible synapomorphy, rugose genital papillae in both males and females. Both species also differ from E. epiphanes by having a short, unbranched fifth ray on the pelvic fins and the absence of the IT pore.

Protogrammus, a new genus of callionymid fishes, with a redescription ofP. sousai from the eastern Atlantic

A new monotypic genus of callionymid fishes,Protogrammus, is described. The type species isCallionymus sousai Maul, 1972. The genus is distinguished from the allied generaChalinops andDiplogrammus by its free opercular flap of skin that is connected to the body in its upper half, a ventrolateral fold of skin consisting of disconnected segments, unbranched rays in the second dorsal and anal fins, and a very small preopercular spine with the formula -11. The only known species,Protogrammus sousai, is redescribed and illustrated.

Varicus imswe, a New Species of Gobiid Fish from Belize

Varicus imswe n. sp. (Gobiidae) is described from two specimens (13.0-13.5 mm SL) collected in 21-25 m of water from an area of well-developed coral at the barrier-reef dropoff east of Carrie-Bow Cay, Belize. Varicus imswe differs from the other two species in the genus, V. bucca and V. marilynae, by its elongated unbranched pelvic-fin rays that are not flattened and fleshy on the tips, its more elongated, tube-like anterior nostril, its steeper profile from interorbital region to tip of snout, its more steeply diagonal mouth, its narrower head, color pattern, and in possessing fewer pectoral-fin rays and elements in the second dorsal fin.

Tres nuevas especies de <i>Bryconamericus</i> (Ostariophysi: Charaddae) de COlombia y diagnóstico del género

Three new fish species are described: Bryconamericus dahli from the basins of the Patia and Mira rivers; B. ichoensis from Chaparraido Creek, the upper Atrato River basin, and B. galvisi from upper Putumayo River. Bryconamericus dahli can be distinguished from other Bryconamericus species by body depth and the larger head. B. dahli is similar to B. caucanus, but can be distinguished by the number of anal fin rays, head width and maxilla. Bryconamericus ichoensis can be distinguished by its small size, absence of a spot on the caudal peduncle, and generally 27 to 30 anal fin rays. B. ichoensis may be closely related to B. multiradiatus, but can be distinguished by the number of unbranched rays in the dorsal, pectoral and pelvic fins, the number of predorsal scales, body depth, etc. Bryconamericus galvisi, can be distinguished from other species of Bryconamericus by its single peduncle spot, high branched anal fin ray, the lateral line scales count, and elongated body. This species is similar to B. caucanus and can be distinguished by the number of teeth on the maxilla and by the number of vertebrae. The genus Bryconamericus is a natural and valid group, which is related to Hemibrycon. Moreover the Knodus and Eretmobrycon are synonym of Bryconamericus.