Molecular and Cytogenetic Analysis of the Goby Gobius Niger (Teleostei, Gobiidae)

A molecular cytogenetic study of Gobius niger has been conducted by treating its mitotic chromosomes with silver-, CMA₃- and DAPI-staining and fluorescent in situ hybridization using four multicopy or repetitive DNAs (the 28S and 5S rDNAs, the TTAGGG telomeric repeat and the mariner-like elements) as probes. In particular, the study proved the presence of NOR heteromorphism and suggested the possible role of the transposable element mariner in its genesis. In situ hybridization with the 5S rDNA probe proved the presence of just one 5S-bringing chromosome pair, whereas hybridization with the telomeric repeat revealed small bright hybridization spots, uniform in size and intensity, on each telomere of all chromosomes but no interstitial signals were noticed. This revised version was published online in July 2006 with corrections to the Cover Date.     

A complex chromosomal polymorphism in Gobius fallax (Gobiidae,Perciformes)

Chromosome analysis of 53 specimens from a population of Gobius fallax has revealed inter- and intra-individual variation in the diploid number (2n=38–43) arising mainly through Robertsonian translocations. The presence of a small biarmed chromosome in a few cells from 3 males as well as the numerous multivalent configurations in meiotic plates and the apparent association between the NOR-chromosomes and other acrocentrics suggest that this polymorphism has an inherited as well as a somatic origin and that some translocations may involve more than two acrocentric pairs simultaneously.     

Courtship Role Reversal in Sevenspine Goby,Gymnogobius heptacanthus (Gobiidae)

Journal of Ichthyology - Females of the sevenspine goby Gymnogobius heptacanthus are more colorful and active in courtship display than males. Females tend to exhibit agonistic behavior in...     

Gobius xoriguer,a new offshore Mediterranean goby (Gobiidae), and phylogenetic relationships within the genus Gobius

Ichthyological Research - Gobius xoriguer sp. nov., a new ofshore species of goby (Teleostei: Gobiidae: Gobiinae) is described based on three specimens collected in 2010, 2012 and 2018 in the...     

Shelter utilization by Gobius cruentatus and Thorogobius ephippiatus (Teleostei: Gobiidae)

Parameters of shelters utilized by Gobius cruentatus and Thorogobius ephippiatus were measured, in situ , using SCUBA. Both species exhibited non-random use of shelters, with T. ephippiatus , the smaller of the two species, utilizing significantly larger shelters than G. cruentatus . Interspecific size differences and competitive exclusion are not considered to be of major importance in the observed differential utilization of shelters. The size of shelters utilized by both species is suggested to be influenced by current velocities.     

Ejaculate of sneaker males is pheromonally inconspicuous in the black goby,Gobius niger (Teleostei,Gobiidae)

The black goby, Gobius niger, shows alternative male mating tactics, i.e., parental and sneaker males. Males release a sexual pheromone that attracts females and stimulates aggressive displays in males. This pheromone is produced by the mesorchial gland, a structure well developed in parental males but markedly undeveloped in sneakers. We measured the behavioral response of parental males to the ejaculates of males performing different reproductive tactics. Parental males reacted to the ejaculate of other parental males, with stereotypic aggressive behaviors, but not to the ejaculate of sneakers; consequently sneaker male ejaculate appears to be pheromonally inconspicuous.     

Feeding strategy of the Deepwater Goby,Chasar bathybius,in the Southern Caspian Sea (Osteichthyes: Gobiidae)

Eleven animal taxa were identified as prey of the Deepwater Goby, Chasar bathybius (Kessler, 1877), by analysing stomach contents: these were some species of Gobiidae, Clupeidae, Atherina boyeri, Carassius gibelio, Liza sp., Cardium sp., and Rhithropanopeus sp. With a frequency of 66%, Neogobius fluviatilis was the most prevalent food item, and was the dominant prey taxon in all seasons and age groups. C. bathybius exhibited a specialist feeding strategy on this fish and the other prey types. The dietary breadth is highest in spring according to the Shannon index.     

Age and growth,reproduction and diet of a sublittoral population of the rock goby Gobius paganellus (Teleostei,Gobiidae)

Colonisation of extremely acidic waters (pH 3) by aquatic angiosperms occurs widely, but is poorly documented. Unlike acid rain affected and other naturally acidic aquatic ecosystems, waters with pH 3 usually have a high conductivity, with high concentrations of SO₄ ^2- and often high concentrations of Fe³⁺, other heavy metal ions and Al³⁺. Where Fe³⁺ concentration is high, as in many mine waters, it provides a strong buffering system. In such waters, the biogeochemical Fe cycle exerts over water chemistry and the availability of nutrients and carbon for organisms. Biological activity is limited by low concentrations of phosphorus and inorganic carbon (DIC), which in this pH range is essentially all in the form of dissolved CO₂. A number of angiosperms grow in such waters including Phragmites australis, Typha spp. and Juncus bulbosus, though the last is the only one reported to grow totally submerged in waters with pH 3 . J. bulbosus occurs in many lignite mining lakes in Lusatia (north eastern Germany) with pH 3. The characteristics and possible survival strategies for this and other species are discussed.     

Age,Growth, Maturation,and Mortality of Grass Goby Zosterisessor ophiocephalus (Gobiidae) of the Karkinitsky Gulf,the Black Sea

Journal of Ichthyology - The sex and size-age structure, growth, maturation, and mortality of grass goby Zosterisessor ophiocephalus have been studied in the Karkinitsky Gulf of the Black Sea. The...     

Histological Studies on the Skin of a Freshwater Goby Rhinogobius brunneus (Gobiidae) Related to Cutaneous Respiration

Journal of Ichthyology - The Korean freshwater goby, Rhinogobius brunneus, prefers shallow water bodies with pebble bottoms, which are easily exposed to air due to the lack of water in droughts or...     

Extended Breeding Season in the Marbled Goby, Pomatoschistus Marmoratus (Teleostei: Gobiidae), in the Venetian Lagoon

Life cycle and reproductive biology of the marbled goby Pomatoschistus marmoratus was studied in the Venetian Lagoon. Lifespan was determined by reading otoliths. The maximum age recorded was 17 months juveniles occurred in samples from July to November. Nests were found in two different periods: from the middle of April to the middle of July and from the middle of August to the end of September. While individuals in a wide range of body size (35–62mm total length) mated during the first spawning peak during the second one only small individuals (28–32mm total length) developed during the first peak were in reproductive activity. Histological analyses showed that most of the juveniles developed during the first spawning peak delayed sexual maturation to the following year. Ripe females appeared to be multiple spawner showing an asynchronous ovary with oocytes at different stages of development. From nesting male body sizes gonadosomatic indices and histological analyses no indication of the presence of alternative male mating tactics emerged.     

Spatiotemporal Distribution and Size Composition of Larvae of the Invasive Round Goby Neogobius melanostomus and of Native Sand Goby Pomatoschistus minutus (Gobiidae) in the Ichthyoplankton of the Southeastern Baltic Sea

Journal of Ichthyology - The larvae of the Ponto-Caspian invader, round goby Neogobius melanostomus, have been first discovered in 2004 in the coastal waters of the Russian sector of the...     

Feeding ecology of the Bay Goby (Pisces: Gobiidae). Effects of behavioral,ontogenetic, and temporal variation on diet

The ontogenetic, diel, seasonal, and yearly variations in gut fullness, diet, and prey diversity for a California estuarine gobiid (Lepidogobius lepidus Girard) were examined. Also the feeding behavior of this species was described.Small (<50 mm, SL) and large (? 50 mm, SL) gobies consumed similar prey types in different proportions. Major prey items were polychaetes, harpacticoid copepods, gammarid amphipods, molluscs, and other crustaceans. Diets of large and small gobies were not significantly correlated, and larger fish had a more diverse diet. Small fish fed at all times while larger gobies fed primarily at night. Changes in diet may be related to differential prey preferences, feeding chronologies, and increases in fish size.Both large and small gobies displayed seasonal differences in diet and prey diversity. Year-to-year changes in diet also were noted for both size classes. The bay goby uses different feeding behaviors to capture sedentary and motile prey and appears to forage opportunistically. This behavior is probably advantageous in an environment which fluctuates drastically.     

The First Finding of an Adult Knout Goby Mesogobius batrachocephalus (Gobiidae) with a Severe Deformity of the Pelvic Suctorial Disc

Journal of Ichthyology - An adult female specimen of the knout goby, Mesogobius batrachocephalus, with a body length of 191 mm, with a severe deformity of the pelvic suctorial disc was discovered...     

Stock Structure, Mortality and Growth of The Decorated Goby, Istigobius decoratus (Gobiidae), at Lizard Island, Great Barrier Reef

Gobiids are an abundant component of coral reef ichthyofauna, yet little is known of their life histories. I examined population structure, mortality and growth of the decorated goby, Istigobius decoratus, a common gobiid of shallow patch reefs on the Great Barrier Reef. Presumed daily increments in sagittal otoliths were used as a proxy for age. The upper age estimate was 266 days suggesting at most an annual life cycle. Instantaneous natural mortality rate estimates were 5.92 year^–1 and 7.92 year^–1 using two estimators, both corresponding to less than 1% annual survivorship. Specimens ranged from 12 to 84 mm total length. Analysis of size-at-age data indicated linear growth at a rate of 0.33 mm day^–1. The linear relationship between size and age meant the population size structure mirrored the age structure with both skewed toward the smallest and youngest classes. High mortality over a 1-year longevity and linear growth suggest high population turnover and, therefore, that I. decoratus and ecologically similar species serve a potentially important role as prey species. This suite of traits is rarely reported for coral reef fishes, which is probably due to the limited attention paid to small-bodied species rather than the rarity of such a life history in these communities.     

Myxobolus albi n. sp. (Myxozoa) from the Gills of the Common Goby Pomatoschistus microps Krøyer (Teleostei: Gobiidae)

ABSTRACT. A recent investigation into the myxozoan fauna of common gobies, Pomatoschistus microps , from the Forth Estuary in Scotland, revealed numerous myxosporean cysts within the gill cartilage. They were composed of polysporous plasmodia containing myxobolid spores that were morphologically different from the other known species of Myxobolus and from the myxosporeans previously recorded from this host (i.e. the ceratomyxid Ellipsomyxa gobii , infecting the gall bladder, and the kudoid Kudoa camarguensis , infecting the muscle tissues). Spores were ovoid, 9.4 × 9.1 μm with a thickness of 6.6 μm, with two pyriform polar capsules, the polar filaments of which had four to five turns. Molecular analysis of the parasite's small subunit rDNA region, based upon a contiguous sequence of 1,558 base pairs, discriminated it from other myxosporean species that have been characterized so far. A comparison of the spore morphology and the molecular sequences determined for this new isolate with other myxozoans described to date, confirmed its identity as a previously unknown myxobolid supporting the proposal that this isolate be elevated to the species level as a new species within the genus Myxobolus . A phylogenetic analysis places this new myxobolid, Myxobolus albi n. sp., in a basal position of a clade containing the majority of Henneguya spp. sequenced to date and various Myxobolus spp.     

Naturalization of the Pacific <Emphasis Type="Italic">Chameleon Goby Tridentiger trigonocephalus</Emphasis> (Perciformes,Gobiidae) in the Black Sea (Crimea,Sevastopol Gulf)

In summer 2008, colonies of the Pacific chameleon goby Tridentiger trigonocephalus were found in the Black Sea in two sites of the Sevastopol Gulf. Data are presented on size-age composition of the caught specimens, morphometric characteristics of females, males, and of immature specimens, and on variants of body coloration depending on physiological state. The number of yolk oocytes of different size and of unfertilized eggs in a clutch is determined. Early ontogenetic stages are described, as well as of behavior of males in the period of care of the egg clutch. Chameleon Goby is naturalized in Sevastopol Gulf and formed a self-reproducing population.