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

Zootaxa ◽  
2020 ◽  
Vol 4762 (1) ◽  
pp. 1-66
Author(s):  
SHUMPEI KAWARADA ◽  
HISASHI IMAMURA ◽  
YOJI NARIMATSU ◽  
GENTO SHINOHARA

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. 

1970 ◽  
Vol 6 (2) ◽  
pp. 349-353 ◽  
Author(s):  
M Begum ◽  
Abdullah Al-Mamun ◽  
ML Islam ◽  
MJ Alam

The morphometric observations were made on total length, standard length, pre-caudal length, head length, eye diameter and depth of body at pectoral fin base of estuarine catfish M. gulio. Males and females showed homogeneity in characters. A linear relationship was found between total length and morphometric characters. Regression of length and weight did not deviate significantly from cube law indicating isometric growth. The fish exhibited sexual dimorphism. Keywords: Morphometric characters; Estuarine catfish; Mystus gulio DOI: 10.3329/jbau.v6i2.4833 J. Bangladesh Agril. Univ. 6(2): 349-353, 2008


Zootaxa ◽  
2021 ◽  
Vol 4996 (2) ◽  
pp. 322-330
Author(s):  
HEOK HEE NG ◽  
MAURICE KOTTELAT

Pseudobagarius eustictus, new species, is described from the Nam Heung drainage (a tributary of the Mekong River) in northern Laos. It is distinguished from congeners in having a unique combination of the following characters: a weakly-produced snout in which the upper jaw extends only slightly beyond the margin of the lower jaw when viewed ventrally, 3 tubercles on the posterior margin of the pectoral spine, eye diameter 8% HL, head width 24.1% SL, dark yellow dorsal and lateral surfaces of the head, pectoral spine lacking elongate extensions, pectoral fin reaching the pelvic-fin base when adpressed against the body, dorsolateral surfaces of body without longitudinal series of prominent tubercles, body depth at anus 13.7% SL, length of adipose-fin base 17.7% SL, caudal-peduncle depth 7.0% SL, and 33 vertebrae.  


2002 ◽  
Vol 45 (3) ◽  
pp. 333-342 ◽  
Author(s):  
Maristela Parra Miranda ◽  
Gentil Vanini de Moraes ◽  
Elias Nunes Martins ◽  
Luis Carlos Pinto Maia ◽  
Orlando Rus Barbosa

Thirty-two eggs of Pantanal caiman (Caiman crocodilus yacare) (Daudin, 1802) were incubated at 30° C. After 20 days of incubation at 30° C, the remaining eggs were distributed in the following way: seven at 34° C, seven at 32° C, six at 30° C and six at 28° C. At 32° C and 34° C a 100% hatchability was obtained while at 30° C 83.3% and at 28° C 66.6%. After hatching, the animals were kept for 120 days at the same temperature of their final incubation. Weight (g) control and morphometric (cm) analysis were carried out. The statistic design was totally randomized and the data were treated by regression analysis showing a quadratic behavior ( p<0.05). It was found that weight, total length (TTL), tail length (TL), snout- vent length (SVL), head length (HL), eye length (EL), snout length (SL), mid-point snout width (MSW), head width (HW), width of snout at nostrils (NW), distance between limbs (DBL) showed a higher development at the temperature range from 31.2° C to 31.8° C and circumference of belly at 30.0° C.


2020 ◽  
Vol 13 (1) ◽  

Spotted stinger individuals, Inimicus sinensis, collected from Carles, Iloilo, Philippines exhibited previously-unreported sexual dimorphism. Thirty-three morphological measurements, including standard length, and fourteen meristic counts from 99 specimens (47 males and 52 females) were analyzed for sexual dimorphism. Most morphometric characters differed significantly between the sexes, whereas no differences were found in meristic counts. Dorsal and anal-fin and free pectoral-fin ray lengths were greater in male specimens. On the other hand, the head and body region were relatively larger in female specimens. Principal Component Analysis (PCA) extracted two principal components from significantly different parameters, which explained 62.29 % of the cumulative variances. Variations in the two major components resulted from: head width, upper jaw, lower jaw, snout, pre-dorsal, pre-anal-fin, and anal-fin base lengths in PC1 (45.65 %); and orbit diameter and anal-fin base length in PC2 (16.64 %). Additionally, a single anterolateral pore on the body and pores above the lateral-line are described, although no evidence of association with other organs was found.


2018 ◽  
Vol 32 ◽  
pp. 5-17
Author(s):  
Hadi Khoshnamvand ◽  
Mansoureh Malekian ◽  
Yazdan Keivany

Morphological differentiation and sexual dimorphism in the two genetically distinct clades (Northern and Southern clades) of the Lorestan newt, Neurergus kaiseri, was evaluated for 72 live specimens, using five body- and nine head-related characters and eight calculated ratios. Principle component analysis of morphological characters confirmed that the Lorestan newt populations are well separated into two distinct groups, suggesting that a taxonomic revision in N. kaiseri may be required because of significant molecular, morphological and ecological differences between these clades. Sexual dimorphism in N. kaiseri includes body size and shape. Females were clearly larger than males in most body- and head-related variables and males had relatively greater head width and eye length. Sexual dimorphism in this species may be linked to sexual selection and ecological differences between sexes. However, many aspects of the ecology and reproductive biology of this species remain unknown.


2019 ◽  
Vol 18 (1) ◽  
pp. 1-15
Author(s):  
A. A. IDOWU ◽  
W. O. ABDUL ◽  
W. O. ABDUL ◽  
A. A. ALIMI ◽  
M. O. TIJANI

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.    


2015 ◽  
Vol 65 (3-4) ◽  
pp. 311-320 ◽  
Author(s):  
João Fabrício Mota Rodrigues ◽  
José Roberto Feitosa Silva

Studies focusing on the natural history of species are essential for developing effective conservation measures and evaluating ecological hypotheses. To this end, we describe natural history data of the Cotinga River toadhead turtle, Phrynops tuberosus, in the Banabuiú River in Ceará, Brazil, and evaluated sexual dimorphism, epibionts, and mutilation effects. We hand-captured 134 individuals by snorkeling, over a period of one year, resulting in the capture of 94 males, 24 females, and 16 juveniles. Females had larger head width and body mass than males, while males had longer tail length. One quarter of the turtles captured had some sort of injury or deformation, most common injuries being missing claws, mutilations, and shell deformations. We found no difference in body condition index between mutilated and non-mutilated animals. Mollusks, insects, and leeches were found as epibionts on P. tuberosus and most of the captured turtles had extensive algal cover. Future studies should focus on understanding the effect of mutilations on animal fitness and reproductive success.


Author(s):  
Daniel Cocan ◽  
Vasile Otel ◽  
Calin Latiu ◽  
Vioara Miresan

In August 2015 we managed to capture a specimen of ratan goby (Ponticola ratan) in the Romanian coastal waters of the Black Sea, near the locality of Sf. Gheorghe (Tulcea County). This is the 7-th signaling for this species in Romanian coastal waters. The previous 6 specimens were recorded in the period 1960-1993, between Mangalia (Constanţa County) and Sulina (Tulcea County). The species was identified by means of meristic characters (number of scales on medial line, number of spiny and soft rays), and morphological particularities (cycloid scales on the nape area and pectoral fin joint). Also, the measurements made, confirmed that the ratio between the head length and total length, which was 33% (TL=8.70 cm vs. Head Length=2.61cm). Another morphological character, specific to this species, is the lower jaw, which exceeds in length the upper jaw. Being a Ponto-Caspian endemite, with low population along the Bulgarian and Romanian coastline, we considered it important to point out this new record. Noting that, being known the trend of sporadic migration of this species, would not be excluded that global warming causes a shift from its normal distribution area, from northern and northeastern (Black Sea) to south-west. Therefore, future research may bring more notifications regarding this species in south-western area of the Black Sea


2014 ◽  
Vol 66 (1) ◽  
pp. 284-288 ◽  
Author(s):  
R.J. Guimarães-Cruz ◽  
V.C. Veloso-Júnior ◽  
N.G. Sales ◽  
D.A.A. Oliveira ◽  
J.E. Santos

The aim of the present study was to characterize the relationships that occur between morphometric variables of larvae of Lophiosilurus alexandri Steindachner, 1876 through their allometric growth analysis. Total length, head length and body height were correlated with standard length, head height and body height, as well as eye diameter and head height with head length. The results revealed allometric positive relation during the initial development, where the b coefficient varied between 1.10 and 2.81. The variable pre-anal distance in relation to the standard length and the snout length in relation to the head length revealed an allometric negative relation, where the b coefficient was 0.85 and 0.94, respectively.


Zootaxa ◽  
2018 ◽  
Vol 4531 (4) ◽  
pp. 451
Author(s):  
DIEGO AGUILAR FACHIN ◽  
MARTIN HAUSER

The Neotropical genus Himantigera James in James & McFadden, 1982, is revised. Two new species are described and illustrated—H. amauroptera nov. sp. (Costa Rica, Panama, Colombia), and H. xanthopoda nov. sp. (Mexico, Nicaragua, Costa Rica). Three species are transferred from Himantigera to Sargus Fabricius, 1798—S. dichrous (Schiner, 1868) comb. nov., S. flavoniger Lindner, 1928 comb. rev. and S. fulvithorax (Bigot, 1879) comb. nov. One species is transferred to Microchrysa Loew, 1855—M. splendens (Schiner, 1868) comb. nov. Himantigera jamesi Lindner, 1969 syn. nov. is proposed as a junior synonym of H. superba Lindner, 1949. The type species H. silvestris McFadden, 1982, as well as H. nigrifemorata Macquart, 1847 and H. superba Lindner, are herein redescribed and illustrated. Photographs of the type specimens of these three species are provided. Two unnamed species of Himantigera (sp. A and sp. B) are also described given that they have slight differences, but because we had only one specimen of each species, we did not officially describe them. This updates the total number of extant Himantigera from eight sensu Woodley (2001) to seven species. The species Merosargus apicalis Lindner, 1935, although never referred to the genus Himantigera or Himantoloba McFadden 1970, is also transferred to the genus Sargus. A key to all species of Himantigera and a map expanding geographical distribution of the genus are also presented, with the first records of the genus for Nicaragua, Colombia, Venezuela, Trinidad and Tobago, Ecuador and Bolivia. 


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