Descriptions of two new shell-dwelling species of Metriaclima (Cichlidae) from Lake Malaŵi, Africa

Metriaclima is the most speciose genus of rock-dwelling fishes (mbuna) found in Lake Malaŵi with 32 described species and with about 40 recognized forms that still await formal description. The genus is comprised of many geographically narrow populations restricted to specific habitat landmarks, such as reefs or islands. A few species have taken to the open sandy habitat where empty gastropod shells provide shelter. Two species of such shell-dwellers are here described as new. A combination of a black submarginal band in the dorsal and anal fins and five or fewer bars on the flank distinguishes Metriaclima ngarae sp. n. and M. gallireyae sp. n. from all other species of Metriaclima. Metriaclima ngarae sp. n. differs from M. gallireyae by a greater interorbital width and by a greater ratio of the snout length in the distance between snout tip and pelvic fin origin. Adult males of M. gallireyae have a blue-brown overall coloration obscuring the bar pattern on the flank while males of M. ngarae and those of the closely related M. lanisticola retain the bar pattern and have a coloration very similar to that of females.

Elastic energy storage in seahorses leads to a unique suction flow dynamics compared to other actinopterygian

Suction feeding is a dominant prey-capture strategy across actinopterygians, consisting of a rapid expansion of the mouth cavity that drives a flow of water containing the prey into the mouth. Suction feeding is a power-hungry behavior, involving the actuation of cranial muscles as well as the anterior third of the fish's swimming muscles. Seahorses, which have reduced swimming muscles, evolved a unique mechanism for elastic energy storage that powers their suction flows. This mechanism allows seahorses to achieve head rotation speeds that are 50 times faster than fish lacking such a mechanism. However, it is unclear how the dynamics of suction flows in seahorses differ from the conserved pattern observed across other actinopterygians, nor how differenced in snout length across seahorses affect these flows. Using flow visualization experiments, we show that seahorses generate suction flows that are 8 times faster than similar-sized fish, and that the temporal patterns of cranial kinematics and suction flows in seahorses differs from the conserved pattern observed across other actinopterygians. However, the spatial patterns retain the conserved actinopterygian characteristics, where suction flows impact a radially symmetric region of ∼1 gape diameter outside the mouth. Within seahorses, increases in snout length were associated with slower suction flows and faster head rotation speeds, resulting in a trade-off between pivot feeding and suction feeding. Overall, this study shows how the unique cranial kinematics in seahorses are manifested in their suction feeding performance, and highlights the trade-offs associated with their unique morphology and mechanics.

A new species of the genus Euphlyctis (Anura: Dicroglossidae) from West Bengal, India

A new species of green frog of the genus Euphlyctis Fitzinger, 1843 is described from West Bengal, a state of eastern India. A robust frog, SVL of male 86mm and that of female 132mm. The species is diagnosed by the presence of following characters: green dorsum and female with a greenish white mid-dorsal line, tibiotarsal articulation reaches eye, male with two vocal sac openings at the junction of jaw, female is larger than male though body parameters is proportionately longer in male, nostril snout length 3.45% of SVL, nostril much closer to snout tip than eye, units of hind limb i. e. thigh, shank and foot are almost equal in length, relative length of finger: II < IV < I < III. The new species is compared with existing eight species of the genus Euphlyctis.

A new species of Diplotaxodon (Cichliformes: Cichlidae) from Lake Malaŵi

A species of haplochromine cichlid fish of the genus Diplotaxodon Trewavas, endemic to Lake Malaŵi is described: Diplotaxodon dentatus, new species. All eight type specimens were trawled together off Thumbi East Island in the Southeastern arm of the lake at 73 meters in 1985. They were initially identified as D. argenteus because the teeth on the oral jaws were fully exposed with a closed mouth. The shorter snout length of D. dentatus (26.6–29.2 % HL) clearly separates it from D. argenteus (31.7–34.2 % HL). A plot of a principal components analysis further supports the separation of D. dentatus from D. argenteus.

Spirlins of the southern Black Sea basin, with the description of a new species (Teleostei: Leuciscidae)

Alburnoides turani, new species, from the Filyos River drainage is described and the distribution of the nine other Alburnoides species known from the southern Black Sea basin is revised. Alburnoides turani is distinguished by having a naked ventral keel, or the keel is covered with 1–3 scales between the posterior pelvic-fin base and the anus, an interorbital distance wider than the eye diameter and the snout length, 48–55 total lateral-line scales, 5–6 scale rows between the anal-fin origin and the lateral line, 13½–14½ branched anal-fin rays, and 41–42 total vertebrae.

Taxonomic revision of the genus Lycenchelys (Osteichthyes: Zoarcidae) in Japanese waters

Eelpout species of the genus Lycenchelys Gill, 1884 recorded from Japanese waters are taxonomically revised. This study recognizes the following 11 species from Japanese waters as valid: Lycenchelys albomaculata Toyoshima, 1983, Lycenchelys aurantiaca Shinohara & Matsuura, 1998, Lycenchelys hippopotamus Schmidt, 1950, Lycenchelys maculata Toyoshima, 1985, Lycenchelys makushok Fedorov & Andriashev, 1993, Lycenchelys melanostomias Toyoshima, 1983, Lycenchelys rassi Andriashev, 1955, Lycenchelys remissaria Fedorov, 1995, Lycenchelys ryukyuensis Shinohara & Anderson, 2007, Lycenchelys squamosa Toyoshima, 1983 and Lycenchelys tohokuensis Anderson & Imamura, 2002. We redescribe species in detail based on type specimens as well as additional specimens in many cases. The synonymy of Lycenchelys brevimaxillaris Toyoshima, 1985 with L. melanostomias is supported in this study. Sexual dimorphism and changes with growth are revealed in L. albomaculata, L. aurantiaca, L. hippopotamus, L. makushok, L. melanostomias and L. rassi, all based on 10 or more specimens, for relative head length, head width, and upper and lower jaw lengths. In addition, we also found that the sizes at which sexual dimorphism can be recognized, and the tendencies for change with growth, differ among species. Furthermore, the dimorphism in head length is influenced by the snout length, eye diameter and/or postorbital length in L. albomaculata and L. aurantiaca.

PRELIMINARY STUDIES ON RED BELLY TILAPIA COPTODON ZILLII CAUGHT FROM OYAN DAM, OGUN STATE, NIGERIA

The study was carried out on the biological aspect of Redbelly Tilapia, Coptodon zillii collected from Oyan Lake, Abeokuta North Local Government Area, Ogun State, Nigeria, with the aim of contributing to the baseline data for carrying out further studies on its ecology, conservation and development. A total of two hundred and fifty four fish (254) specimens were caught from the Ibaro landing site of the Lake between March and July, 2015. The total length (cm), standard length (cm), head length (cm), body width (cm), body depth (cm), snout length (cm), eye diameter (cm) and body weight (g) were measured. The stomach content was also assessed in order to determine its food and feeding habit. The mean total-length, standard-length, head-length, eye-diameter, snout-length, body-depth, body-width and body-weight during the study were 10.98±0.61cm, 8.56±0.14cm, 2.5±0.08cm, 3.67±0.15cm, 1.52±0.11cm,1.37±0.17cm, 4.05±0.07cm, 34.25±3.02g respectively and their ranges were (4.5-18.7cm), (3.2-15.2cm), (1.1-5.8cm), (2.0-6.8cm), (0.8-3.0cm), (1.1-4.8cm), (1.4-7.3cm) and (6.0-132.0g). A negative allometric (b<3) growth pattern was observed for the stock. The meristic characteristics of C. zillii were (DFR) XIV 10 – XVI 14; PVR, AFR III 8 –III 9; PFR 10 – 13 respectively. Stomach analysis showed that diatoms were the most abundant food items in the diet of C. zillii numerically, 29.98%, while desmids were the most abundant food items in terms of frequency occurrence, 27.82%. This study concluded that C. zillii is not morphometrically and meristically different from the already classified from previous studies. Also, C. zillii thrives well on available plants and detritus.

Morphological differences between species of the sea bass genus Lateolabrax (Teleostei, Perciformes), with particular emphasis on growth-related changes

Morphological differences, including growth-related changes, were examined in three morphologically similar East Asian sea bass species,Lateolabraxjaponicus,L.maculatusandL.latus. In many cases, body measurements indicated specific patterns of growth-related proportional changes.Lateolabraxlatusdiffered from the other two species in having greater body depth, caudal peduncle depth, caudal peduncle anterior depth, snout length, and upper and lower jaw length proportions. In particular, scatter plots for caudal peduncle anterior depth relative to standard length (SL) in that species indicated complete separation from those of the other two species, being a new key character for identification. Comparisons ofL.japonicusandL.maculatusrevealed considerable proportional differences in many length-measured characters, including fin lengths (first and second dorsal, caudal and pelvic), snout length, post-orbital preopercular width (POPW) and post-orbital length. In particular, snout length (SNL) and POPW proportions of the former were greater and smaller for specimens &gt;200 and ≤ 200 mm SL, respectively. Because the scatter plots of these proportions for the two species did not overlap each other in either size range, identification of the species was possible using a combination of the two characters. In addition, scatter plots of the POPW / SNL proportion (%) ofL.japonicusandL.maculatuswere almost completely separated throughout the entire size range examined (border level 90%), a further aid to identification. The numbers of pored lateral line scales and scales above the lateral line tended to increase and decrease with growth, respectively, inL.japonicus, whereas scales below the lateral line and gill raker numbers tended to increase with growth inL.maculatus. Because the ranges of these meristic characters may therefore vary with specimen size, they are unsuitable for use as key characters. Accordingly, a new key is proposed for the genusLateolabrax.

Projected effects of temperature changes on the Italian Western Tauri glaciers (Eastern Alps)

ABSTRACTA linear model was used to investigate the behaviour of the Italian Western Tauri glaciers as a result of temperature changes projected for the 21st century. The model estimates the temperature variations once the glacier snout length variations are known and vice versa: it estimates the glacier snout length variations once the air temperature variations are known or predicted. The 46 glaciers of the Italian Western Tauri, 35 (76%) of which have areas smaller than 0.5 km2 and only 7 (15%) larger than 1 km2, are mostly mountain type glaciers and only three are presently valley glaciers. The model has been forced by the air temperature projections of the A1B emission scenario, which indicates an increase in temperature of 2.7°C from 2015 to 2100. The results show a shortening of more than 35% for mountain glaciers by 2100 with a surface loss of more than 60% and smaller reductions for valley glaciers. The consequent fragmentation into smaller units would lead to the extinction of 95% of the existing glaciers by the end of the century, possibly leaving only the valley glaciers surviving.

ALLOMETRIC GROWTH IN BRAZILIAN NATURALIZED PIGS

The allometric growth of male and female naturalized pig breeds (Nilo, Piau, Moura, and Monteiro) was evaluated regarding hip height, snout length, and head length using the allometric equation. Body measurements generally show later growth in relation to the snout length and earlier growth in relation to the head length and hip height. When comparing breeds of pigs, female Moura animals showed later growth of the characteristics linked to muscle (thoracic circumference, body length, and longitudinal diameter) than of head length. Nilo females showed characteristics such as shoulder length, rump length and interschiadic distance earlier than snout length. There were differences between the breed and gender in terms of development times for the different parts of the body, showing that breeding systems and use of these animals have to be specific for each breed.