Journal of Ichthyology最新文献

The study of diversity in characters of the skull in generalized and specialized morphotypes of the large African barbs Barbus (Labeobarbus auctorum) in Ethiopia is carried out using the multivariate analysis methods. It has been proven that in Lake Tana exhibiting great diversity in morphotypes, the eigenvector loadings on the first principal component of characters of bones, which form the jaws, compose a distinct self-standing cluster in specimens of a generalized form reaching over 15 cm in length. In barbs inhabiting other lakes, where only a generalized form is found, the lack of such cluster is observed, while the eigenvector loadings on the second principal component generate a cluster similar in composition. The same pattern is discovered in the Altai osmans (genus Oreoleuciscus) in Lake Orog within the Central Asian Closed Basin (Mongolia). In this case, however, the specimens of the generalized form tend to exhibit the characters of a bigmouth form after transition to feeding on fish whereas the progeny of bigmouth barbs in Lake Tana exhibit the parental characters even in the aquarium-based experiments. It is assumed that in the Altai osmans from Lake Orog we observe an early stage of morpho-ecological divergence between forms, when it is still reversible, while the divergence at a later stage, when it is irreversible, is detected in the barbs from Lake Tana, which may be regarded as an example of genetic assimilation.

Abstract

The inner ear position and structure, related parts of the brain and neurocranium, as well as the morphology of the lapillus, sagitta, and asteriscus, are described in climbing perch, an obligate air-breathing fish capable of terrestrial movements. The olfactory bulbs and telencephalon are well developed. The dorsal protrusion with two symmetrical lobes is observed on the dorsal posterior surface of the telencephalon. The almost triangular rear part of the brain capsule and a narrow posterior region of the neurocranium represent the border of the suprabranchial chamber. The pars superior of the inner ear is located along the internal triangular part of the brain capsule, and both crus communis and ductus semicircularis posterior are located close to each other in the narrow extreme rear region of the brain capsule. The sacculus is enclosed in the large oval bony capsule (saccular swelling), and the sagitta is large with the average otolith length–total body length (TL) ratio equal to 0.06. Linear growth of the lapillus and sagitta is characterized by negative allometry in relation to body length. Despite the slow growth rate of the lapillus, its shape substantially changes during the growth of the fish 36–205 mm TL that, most likely, reflects increasing locomotion complexity. Possible adaptations of climbing perch inner ear to terrestrial movements are discussed.

Abstract

The article presents an illustrated description of early larvae of the smooth lumpsucker Aptocyclus ventricosus from Avacha Bay and Vilyuchinskaya Bay in southeastern coast of Kamchatka. The larvae differ from previously described larvae from Japanese and Korean waters in their earlier development: the urostyle bending, the formation of fin rays, and the development of pigmentation occur earlier. The growth of the larvae is uneven. The head and torso increase in relation to the length of the body, while the tail part practically does not grow. Eye diameter, maxillary length, and the length of the pectoral fin rays relatively decrease. The first dorsal fin is difficult to distinguish, which can cause difficulties in the larva diagnoses. The larvae are coastal, lead an attached lifestyle.

Abstract—

The structure of the olfactory organ is studied in five species of anemonefishes of the genus Amphiprion: A. polymnus, A. clarkii, A. frenatus, A. perideraion, and A. ocellaris. All fish have one nostril, olfactory rosette of the arrow-shaped type with no secondary folding on olfactory lamellae, and two ventilation sacs (ethmoidal and larger lacrimal). The rosette is located on the medial (A. clarkii and A. perideraion) or ventromedial (A. polymnus, A. frenatus, and A. ocellaris) sides of the olfactory cavity; the number of lamellae in the rosette increases as a fish grows. The greatest total number of lamellae is 24 in A. polymnus. Intercalary (in four species) and dichotomous (in three species) lamellae are found in the rosette of most anemonefishes, which is an extremely rare case in other fishes. Atypical lamellae emerge later than regular ones in the ontogeny of the fish, but their number in different parts of the rosette differs between anemonefishes, and in some A. polymnus species, lamellae are predominantly atypical. The slope of the medial and lateral sides of the rosette toward the openings of the ventilation sacs (A. polymnus and A. frenatus) is considered a structural adaptation that improves water exchange near the surface of the olfactory lamellae and reception of odor information by the fish. The relationship between the structure of the olfactory organ and the generality of anemonefishes, their specialization, and strength of association with symbiotic sea anemones has not been revealed. The idea of an evolutionary trend from a simple structure of the olfactory organ (A. clarkii) to a morphologically more complex structure (A. polymnus and A. frenatus) in the genus Amphiprion after early separation from the general stem of the subgenus Actinicola (A. ocellaris and A. percula) is presented.

Abstract

The palatability of L-α- and D-α-isomers of alanine, aspartic and glutamic acids, and tryptophan, as well as L-α- and L-β-isomers of alanine for the Mozambique and Nile tilapias (Oreochromis mossambicus and O. niloticus, respectively), golden mbuna Melanochromis auratus, lemon cichlid Neolamprologus leleupi, and the tailbar cichlid Vieja hartwegi has been compared. Consumption of agar-agar pellets with L-α- and D‑α-isomers of aspartic and glutamic acids and tryptophan differs in Mozambique tilapia and tailbar cichlid, pellets with alanine and tryptophan, in golden mbuna, with aspartic acid and tryptophan, in lemon cichlid, and with aspartic acid, in Nile tilapia. The palatability of L-α- and L-β-isomers of alanine is significantly different for the Mozambique tilapia, lemon cichlid and tailbar cichlid. The feeding behavior exhibited by cichlids during orosensory testing of pellets is similar and little depends on the palatability of the pellets. All cichlids make a small number of rejections and repeated grasps of pellets; most cichlids retain pellets in the oral cavity many times longer in experiments that ended by consumption. The different taste properties of optical and structural isomers of amino acids for the studied cichlids confirm the species specificity of taste preferences in fish and indicate the importance of these substances as chemical regulators of trophic relationships in aquatic communities.

Abstract

The paper describes the first finding of the European hake Merluccius merluccius (Linnaeus, 1758) in the northern part of the Black Sea, off the coast of Crimea, in December 2022 with a sea surface temperature of 13°C. The individual was found in the catch of a bottom trap installed at a depth of 24 m. The specimen with a total body length of 30.6 cm and a weight of 213.5 g was a sexually mature 3 years old male. According to the results of back-calculations obtained during the analysis of the otolith section, the individual growth of the caught fish occurred as follows: the total length was 17.7, 25.5, and 30.6 cm by the end of the first, second, and third years of life, respectively. No food items have been found in the gastrointestinal tract of the caught specimen. The geographical variability of the hake life cycle is considered. The species reaches its maximum size and age at high latitudes and at low water temperatures. Presumably, the maximum size and age of the hake in the Black Sea may be slightly higher than in the Mediterranean Sea, but lower than in the Northeast Atlantic. The prospects for further resettlement and increase in the number of the hake in the Black Sea are analyzed. Apparently, low salinity and competition with the native ichthyofauna may prevent successful naturalization of the species. However, the continuation of the trend of increasing salinity of the Black Sea under warming conditions will increase the possibilities of the hake naturalization.

Abstract

This study investigated the sagittal otolith morphometry of the red mullet Mullus barbatus inhabiting the Aegean, Black Sea and Mediterranean coastal waters of Turkiey. In the comparison of otolith shape of M. barbatus, elliptic Fourier and Wavelet analyses were used as well as otolith shape indices with multivariate statistical techniques. Totally, 180 specimens were examined for otolith shape analyses. Otolith shape indices, including form factor, aspect ratio, circularity, roundness, and rectangularity, have been determined. A principal component analysis and canonical discriminant analysis were carried out for the discrimination of the three M. barbatus populations. The PERMANOVA test was used to evaluate differences between populations. The overall classification success for the canonical discriminant analysis in separating red mullet in these three seas was 53.9% in elliptic Fourier analysis and 57.8% in wavelet analysis. The Aegean and Mediterranean Seas have the highest classification success rates, at 65%. Elliptic Fourier analyses (68.6%) separated the Black Sea from the Mediterranean and Aegean Seas while Wavelet analyses (69.3%) separated the Aegean Sea from the Mediterranean and Black Seas.

Abstract

A new species, Triplophysa shannanensis sp. nov., is described from the Yarlung Tsangpo-Brahmaputra River based on morphological and genetic analyses. The new species is distinguished from its congeners by the following combination of characters: posterior chamber of swim bladder developed, ovoid, directly connects to the anterior chamber; intestine short, zigzag-shaped and with two loops; lower jaw spoon-like, blunt, and covered by lips; snout length shorter than postorbital length; dorsal fin origin anterior to the ventral fin origin, and it closer to caudal fin base than tip of snout; the pelvic origin is just below vertical from the second branched dorsal fin ray, and tips of ventral fin reaching to anus or close to anal fin origin; vertebrae 4 + 36–38; gill rakers 10–11. Molecular phylogenetic analysis indicated that the new species is situated in the most basal of the genus Triplophysa species distributed in the Himalayan region of China. The Kimura’s 2-parameter interspecific genetic distance of the cytochrome b gene sequences of the new species differed from 5.6 to 20.3% with other Triplophysa species. Two non-native species, T. dalaica and T. scleroptera, were first found in the the Yarlung Tsangpo River, which would bring the number of Triplophysa in the Tibetan Himalaya of China to eleven species. A checklist of genus Triplophysa in Chinese Himalaya was further provided.

Abstract

Otolith abnormalities and bilateral asymmetry are analyzed in five reproductively isolated forms and natural F1 hybrids between the forms in Arctic charr Salvelinus alpinus complex from lakes Lama and Kapchuk (Norilo-Pyasinskaya water system, Taimyr). Otolith abnormalities are associated with the partial replacement of aragonite (the usual otolithic polymorph of CaCO₃) by vaterite (another less stable crystalline modification of CaCO₃) and their unusual shape. The abnormalities are observed in 11.9% of the specimens and may be induced by technogenic pollution from Nornickel, the world’s largest manufacturer of palladium, nickel, and platinum. The assessment of bilateral asymmetry based on otolith measurements and shape indices does not indicate notable differences in this parameter between the charr forms. However, the shapes of the left and right otoliths described by wavelet analysis are significantly different in two groups: a form of Lake Kapchuk designated as the main form and F1 hybrids. The differentiation of the forms is evaluated using wavelet and linear discriminant analyses of otolith shape. The difference in the topologies of two dendrograms constructed based on the shapes of the left and right otoliths obtained from the same specimens can be explained by the occurrence of bilateral asymmetry.