Gobiid Fish Research Articles

Interactions among multiple selective pressures on the form–function relationship in insular stream fishes

Abstract Relationships between body shape and escape performance are well established for many species. However, organisms can face multiple selection pressures that might impose competing demands. Many fishes use fast starts for escaping predator attacks, whereas some species of gobiid fishes have evolved the ability to climb waterfalls out of predator-dense habitats. The ancestral ‘powerburst’ climbing mechanism uses lateral body undulations to move up waterfalls, whereas a derived ‘inching’ mechanism uses rectilinear locomotion. We examined whether fast-start performance is impacted by selection imposed from the new functional demands of climbing. We predicted that non-climbing species would show morphology and fast-start performance that facilitate predator evasion, because these fish live consistently with predators and are not constrained by the demands of climbing. We also predicted that, by using lateral undulations, powerburst climbers would show escape performance superior to that of inchers. We compared fast starts and body shape across six goby species. As predicted, non-climbing fish exhibited distinct morphology and responded more frequently to an attack stimulus than climbing species. Contrary to our predictions, we found no differences in escape performance among climbing styles. These results indicate that selection for a competing pressure need not limit the ability of prey to escape predator attacks.

A revision of the gobiid fish genus Pseudogobius/ (Teleostei, Gobiidae, Tridentigerinae), with description of seven new species from Australia and South-east Asia.

The tridentigerine genus Pseudogobius is widespread, from temperate to tropical areas of the Indo-west Pacific. A morphological review of the genus was carried out, with the initial focus on South-east Asian and Australian species. There are about 21 nominal species in the genus; however, the type specimens for some nominal species are missing. Our work recognises 15 valid species so far, including seven new species, which are described herein: P. aquilonius n. sp., P. cinctus n. sp., P. eos n. sp., P. hoesei n. sp., P. jeffi n. sp., P. rhizophora n. sp. and P. verticalis n. sp. We also conclude that P. poicilosoma (Bleeker, 1849) is the senior synonym of P. javanicus (Bleeker, 1856). Pseudogobius poicilosoma, P. gastrospilos (Bleeker, 1853) and P. javanicus are accepted here as conspecific, although the types are in poor condition (note that all three names were given to specimens collected within close proximity to each other in coastal Java, Indonesia). A key to valid species is presented. The revision benefited from an adaptive feedback loop with companion genetic analyses, with the most comprehensive data available for the Australian region. Broader preliminary genetic data suggest the potential for recognition of additional cryptic species, with the current study providing a platform for future systematic work. Pseudogobius are a prominent part of estuarine biodiversity in the Indo-west Pacific, and this study helps to highlight the need to better understand the taxonomy and conservation requirements of cryptobenthic fishes.

Biodiversitas ikan Amfidromus Gobiidae di Perairan Indonesia

Gobiidae fish are distributed widely in tropical and subtropical waters, and inhabit almost all benthic habitats ranging from freshwater, intertidal to offshore, with varied substrates such as muddy bottom, rocky, and coral beds. The diets of Gobiidae varies greatly, from microalgae to small fish. The life cycle follows the amphidromus migration pattern, the mature Gobiidae spawn in fresh water and the hatched larvae drift to brackish waters or to the sea, and will return to fresh water in a few weeks or months later. Species of Gobiidae varies greatly in Indonesian waters. The species composition of Gobiid fish schooling varies greatly by location and by seasonal appearance in estuary waters.

Ultrastructure of the Anisakid nematode, Raphidascaroides sp (Nematoda: Anisakidae) from the freshwater fish Rhinogobius ocellatus (Fowler, 1937) with attendant histopathological alterations in Lekki Lagoon, Lagos, Nigeria

The objective of this study is to report the parasitic infections in the gobiid fish with histopathogical changes and the SEM description of the recovered parasites for possible unreported morphological details and for the purpose of control measures in the fish species. Fishes were procured, dissected and examined parasitologically. The nematode, Raphidascaroides sp was the only recovered parasite from the intestine of the gobiid fish. Fixation of the parasites was done in 2.5% glutaldehyde and were post fixed in 1% Osmium tetraoxide, sputter coated and examined with the Scanning Electron Microscope. The infected tissues were also fixed in Bouins fluid.The overall prevalence of infections was 70.7%. Male specimens of the fish species were more susceptible to infections (71.4%) than the female specimens (66.6.) The Raphidascaroides sp. ultrastructure revealed three lips with dentigerous ridges.The two ventrolateral lips measures 68.6 and 69.7 µm while the third lip has a length of 55.1 µm with corresponding breadth of 66.0 µm, 40.5 µm and 59.3 µm respectively. The histopathological alterations in the fish species revealed goblet cell hyperplasia and moderate lymphocytic infiltration of the lamina propria.The dominant and only parasite recovered from the fish host is Raphidascaroides sp, an anisakid nematode whose pathological consequences is mild owing to lack of holdfast organs in nematodes. The ultrastructural description of the parasites is the first report in Nigeria. There is a conclusion that there may be similar food and feeding habits of the fish, Rhinogobius ocellatus with Gymnarchus niloticus with a report of the same parasites in its intestinal mucosa.

Otolith measurements to estimate standard length of gobiid fish (Teleostei: Gobiiformes) from the Persian Gulf and Oman Sea

The relationship between morphometric characters (length, weight and height) of otolith and fish standard length was determined for six intertidal gobiid species from the northern Persian Gulf and Oman Sea. A total of 144 sagittal otoliths were extracted and anlysed from Periophthalmus waltoni, Boleophthalmus dussumieri, Scartelaos tenuis, Istigobius ornatus, Bathygobius meggitti and Trypauchen vagina. Regression equations were derived and found that there is no significant difference in regression coefficients between left and right otoliths of the species studied. Results of the study showed that otolith length (OL) and height (OH) could estimate standard length in all the species studied except in T. vagina, where the otolith weight gave the best estimate of standard length. Results clearly indicated that otolith dimensions of the gobiid fishes studied could provide information about the species and size.

The cryptic cornucopia revisited– an extended analysis of the COI gene in the gobiid fish genus Trimma (Percomorpha: Gobiiformes)

The cryptic cornucopia revisited– an extended analysis of the COI gene in the gobiid fish genus Trimma (Percomorpha: Gobiiformes)

Comparative ultrastructure and ornamentation characteristics of scales in gobiid species (Teleostei: Gobiidae) using the scanning electron microscope.

To study scale based phylogenetic affinity, the ultrastructure and ornamentation characteristics of body key scales were studied for 12 gobiid species from the Iranian coast of the Persian Gulf including Qeshm and Hormuz Islands and the Makran coast of the Oman Sea using scanning electron microscopy (SEM) technique. The scales were removed from below the first dorsal fin, cleaned in potassium hydroxide solution 1%, and were prepared for the SEM imaging. The presence of both ctenoid and cycloid scales in the studied gobiids was revealed. The focus of ctenoid scales was positioned posteriorly, while the focus of cycloid scales was positioned in the postero-central part of the scale. In all the studied species, radii were located only on the anterior part of the scale, and the primary radii were dominant. Also, there were no granules in the inter circular space, but bifurcation was observed in some circuli. In most species, the teeth-like structures called lepidonts were present on the crest of circuli, which functionally help to firmly attach the scales to the epithelium. The dendrogram of the between-groups-linkage method sorted the gobiid species into the two main groups of five distinct clusters: (a) Cryptocentroides arabicus and Cryptocentrus cyanotaenia (the Cryptocentrus-lineage); (b) Bathygobius meggitti and Bathygobius cocosensis (the Glossogobius-lineage); (c) Coryogalops adamsoni and Coryogalops tessellatus (the Gobius-lineage); (d) Acentrogobius dayi, Istigobius ornatus, Favonigobius reichei, Aulopareia ocellata, and Silhouettea ghazalae (the Gobiopsis-lineage). It seems that the dendrogram topology obtained based on the macro-and microscopic structures of scales, reveals phylogenetic lineages of gobies that have already been proposed for these taxa. Hence, the results of this study are largely consistent with the previous molecular studies on the gobiid fishes and implied that besides other data, the analysis of scale shape and scale-surface microstructures could be served to study the diversification of gobiid species.

Species composition and biodiversity index of gobiid assemblage in estuarine areas of the Mekong Delta, Vietnam

The interaction between environmental factors and the distribution of gobiid fishes was investigated at 16 sampling sites in estuarine areas of the Mekong Delta, Vietnam. Fish specimens were mainly collected by using trawl net, push net, and bag net every two months, from August 2017 to August 2019. Data analysis showed that 40 fish species belong to three families in the gobiid assemblage in the studied area. The most common family was Gobiidae (62%), followed by Oxudercidae (25%) and Eleotridae (13%). The number of fish species decreased gradually from estuary to midstream of river systems. The gobiid assemblage was more diversified in the river system controlled by the West Sea (37 species and 696 individuals) than in the river planned by the East Sea (17 species and 225 individuals). The fish species and biodiversity indexes decreased with the reduction of salinity from the estuary to the midstream of the river system. In the wet season, the fish assemblage was more abundant and diverse than in the dry season due to the environmental factors influenced by the Mekong River. The highest biodiversity index was recorded in Bay Hap and Ong Trang (77.38%). Moreover, the analyzed result of biodiversity indexes revealed that the diversity of fish species in the study area was relatively high. The study outcome will be useful in fisheries management and biodiversity conservation, especially for estuaries.

Foraging behavior of yellow-phase Japanese eels between connected fresh- and brackish water habitats

Japanese eels (Anguilla japonica) utilize a broad range of habitats along the marine-freshwater ecotone during their growth phase in inland waters. This study aimed to analyze the foraging behavior of yellow-phase Japanese eels in connected fresh- and brackish water habitats and to connect foraging behavior and habitat use through the analysis of carbon (δ13C) and nitrogen (δ15N) stable isotopes. Stomach contents of eels collected in fresh- and brackish waters were analyzed to identify food sources. Values of δ13C and δ15N were analyzed in eels and their potential food sources, and used to predict the recent foraging patterns of eels in the Matsukawa-ura, a brackish water lagoon, and in three freshwater tributaries. Eels preyed on the benthic river community and the mudflat community of the lagoon. Gobiid fishes were found to be an important food source for eels in fresh- and brackish water habitats, while Japanese mitten crabs (Eriocheir japonica) and shore crabs (Hemigrapsus spp.) were major prey in fresh- and brackish waters respectively. δ13C values of potential eel prey differed significantly between fresh- and brackish waters and were used to classify three recent patterns of foraging by the 73 eels included in this study: 1) freshwater foraging, 2) brackish water foraging, and 3) multiple-habitat foraging. The data suggested that some eels recently or frequently moved between fresh- and brackish water habitats while others demonstrated a higher fidelity to either fresh- or brackish waters. Isotopic characteristics of prey in the respective foraging habitats revealed the plasticity of habitat use of yellow eels in the study area. This study demonstrates an integrated approach to study habitat use and foraging behavior of eels. Furthermore, the study underlines the need to consider freshwater and estuarine habitats and the connectivity between them for eel management and conservation.

Shape variation and functional adaptation in a structure involved in the feeding system of gobiid fishes

AbstractFish are observed in different aquatic environments, including freshwater, marine and also intertidal zones. It is suggested that the urohyal bone is involved in the feeding function of fish. Information about the urohyal bone in different fish groups, including gobiids is rare. In the present study, changes in the shape of the urohyal bone were studied in seven gobiid fish from the intertidal environments of the Persian Gulf and the Gulf of Oman by applying shape analysis and geometric morphometric analyses. The results revealed that the shape of the urohyal bone in each species was distinct, which is almost consistent with their phylogenetic relationships. Periophthalmus waltoni inhabits often terrestrial habitats and requires a system to obtain food. The specific shape of the urohyal bone in this species probably results from a functional adaptation to obtain food from the terrestrial environment. Moreover, our results indicated that the shape variation in the urohyal bone of the studied species is linked to their feeding because the calculation of E index categorized those species with similar feeding regimes into one group. In conclusion, we assumed that the urohyal shape variation in the studied gobiid species is the result of compatibility to the various feeding regimes, and it is likely controlled by genetic factors. Furthermore, the results support the usefulness of the urohyal bone morphology in differentiating the studied gobiid species and highlighting the taxonomic value of the urohyal bone.

Group structure and putative mating system of three hermaphrodite gobiid fish, Priolepis akihitoi, Trimma emeryi, and Trimma hayashii (Actinopterygii: Gobiiformes)

We investigated the mating system of three sex changing gobiid fishes: Priolepis akihitoi, Trimma emeryi, and Trimma hayashii by underwater observation or specimen collection. P. akihitoi were found in pairs or were solitary. As the pair bond persisted for at least two months, and pair individuals seemed to mate with each other repeatedly, a monogamous mating system was suggested in P. akihitoi. In contrast, the harem-like group (living in a group composed of one largest male and some smaller females and/or immature individuals) of T. hayashii and T. emeryi suggested that these species have harem polygyny.

Functional correlations of axial muscle fiber type proportions in the waterfall-climbing Hawaiian stream fish Sicyopterus stimpsoni.

Assessing the factors that contribute to successful locomotor performance can provide critical insight into how animals survive in challenging habitats. Locomotion is powered by muscles, so that differences in the relative proportions of red (slow-oxidative) vs. white (fast-glycolytic) fibers can have significant implications for locomotor performance. We compared the relative proportions of axial red muscle fibers between groups of juveniles of the amphidromous gobiid fish, Sicyopterus stimpsoni, from the Hawaiian Islands. Juveniles of this species migrate from the ocean into freshwater streams, navigating through a gauntlet of predators that require rapid escape responses, before reaching waterfalls which must be climbed (using a slow, inching behavior) to reach adult breeding habitats. We found that fish from Kaua'i have a smaller proportion of red fibers in their tail muscles than fish from Hawai'i, matching expectations based on the longer pre-waterfall stream reaches of Kaua'i that could increase exposure to predators, making reduction of red muscle and increases in white muscle advantageous. However, no difference in red muscle proportions was identified between fish that were either successful or unsuccessful in scaling model waterfalls during laboratory climbing trials, suggesting that proportions of red muscle are near a localized fitness peak among Hawaiian individuals.

Assessing trophic relationships between shallow-water black corals (Antipatharia) and their symbionts using stable isotopes

Shallow-water antipatharians host many symbiotic species, which spend their adult life with their host and/or use them to have access to food. Here we determine the trophic relationships between four common macrosymbionts observed on/in Cirripathes anguina, Cirrhipathes densiflora and Stichopathes maldivensis in SW Madagascar. These include the myzostomid Eenymeenymyzostoma nigrocorallium, the gobiid fish Bryaninops yongei, and two palaemonid shrimps, Pontonides unciger and Periclimenes sp. The first is an endosymbiont living in the digestive tract, while the others are ectosymbionts. The analyses show that most likely (i) none of the symbionts uses the host as a main food source, (ii) nocturnal plankton represents a main part of the diet of antipatharians while the symbionts feed preferentially on diurnal plankton, (iii) the myzostomid has the narrowest trophic niche, (iv) the two shrimps have distinct trophic niches and feed at lower trophic level than do the other symbionts. Concerning the myzostomids, they had the same δ13C values but had significantly higher δ15N values than the hosts. TEFs (Trophic Enrichment Factors) recorded were Δ13C = 0.28 ± 0.25 ‰ and Δ15N = 0.51 ± 0.37 ‰, but these were not high enough to explain a predator-prey relationship. These worms rely on the coral diet but may also ingest host fluids explaining the slight enrichment in heavier nitrogen isotopes. On the other hand, the ectosymbionts use the coral as a pathway to have access to food from the midwater: they feed from the water passing nearby the black corals, but a kleptoparasitic behaviour cannot be excluded.

Length‐weight relationships of six tropical estuarine fish species from Pulicat lagoon, India

Length–weight relationships (LWRs) of six finfish species under two families of the order Perciformes collected from Pulicat lagoon (India) are presented in this study. The fish specimens were collected weekly from the catches of shore seine net (with a mesh size of 50mm at the main webbing and 10 mm at the cod end) operated in the lagoon at an average depth of 2.5 m by the local fishermen during the period from July 2018 to April 2019. This study reports the LWRs for five gobiid and one siganid fish species which have no earlier reports on LWRs. The calculated ‘b’ value ranged from 3.538 (Favonigobius reichei) to 2.677 (Oxyurichthys microlepis) and ‘a’ value varied from 0.0041 (Favonigobius reichei) to 0.0199 (Acentrogobius cyanomos). This study also reports the new maximum total length (TLₘₐₓ) for the gobiid fish species Oxyurichthys microlepis.

Diet of Glossogobius callidus (Teleostei: Gobiidae) in freshwater impoundments in the Sundays River Valley of the Eastern Cape, South Africa

Despite the high abundance of the gobiid fish Glossogobius callidus in many freshwater ecosystems in South Africa, very few studies have assessed the biology and ecology of the species. Here, we investigated the diet of G. callidus populations sourced from Sundays River irrigation ponds. A total of 571 fish grouped into two size classes (TL, range ± SD: juveniles of 20–60 ± 45 mm; adults of 61–140 ± 85 mm) were sampled by seine netting; prey items were removed from the guts and identified and sorted to obtain dietary information for each prey group. Of the examined guts, 97% contained prey comprising 17 taxa within 10 taxonomic groups. Teleosts were identified to species level, whereas most dietary components were identified to a broad taxonomic group. Aquatic invertebrates were the most important component of the diet of G. callidus, but the index of relative importance (%IRI) of dominant invertebrate taxa varied according to ontogenetic stage of G. callidus and season. Prey taxa included: Diptera, Hemiptera, Trichoptera, Odonata, Cladocera, Copepoda, Hydracarina, Amphipoda, Mollusca and Teleostei. Dipteran prey taxa were consistently encountered in both size classes and across all seasons. G. callidus can therefore be regarded as a generalist invertivore.

Evaluation of parasites associated with mudskipper <i>Periophthalmus spp.</i> sold in selected waterfronts market in Port Harcourt Metropolis, Rivers State, Nigeria

Evaluation of parasites associated with mudskipper Periophthalmus spp. sold in selected waterfront markets in Port Harcourt metropolis, Rivers State, was undertaken. A total of 110 live mudskippers were sampled and examined for the presence of ecto- and endo-parasites. The gobiid fish sampled were identified into three species; P. modestus, P. koelreuteric and P. papilio. The mean length and weight were noted, pectoral fins, gills and intestine were examined for the presence of parasites. The abdominal cavities and mesenteries were examined for migratory juvenile nematodes and metacercariae. Normal saline was used to process gut content for microscopic examination. Inferential statistics was used to analyze data. Result revealed that P. modestus, P. papilio and P. keulreuteric had prevalences of 80.0%, 76.7% and 86.0% respectively. The parasites encountered were Dactylogyrus spp. and Gyrodactylus spp. (Monogeneans); Diplostomium spp. (Digenean); Diphyllobotrium spp. and Proteocephaus spp. (Cestodes) and Capillaria spp., Goezia spp. and Daemodora spp. (Nematodes). The result showed that Capillaria spp. had the highest parasite mean intensity and parasite mean abundance of 2.71 and 1.04 respectively. Also, Goezia had the highest parasite mean prevalence of 50%. At p>0.05, the endo-parasites were statistically significant level.Keywords: Parasites; Periophthalmus spp.

Geographical distribution and population genetic structure of the gobiid fish Gymnogobius sp. 2, formerly known as Gymnogobius cf. castaneus “Toyama-endemic”

The geographical distribution and population genetic structure of the endangered freshwater goby Gymnogobius sp. 2 sensu Akihito et al. (2013) (formerly known as Gymnogobius cf. castaneus “Toyama-endemic”) were investigated via extensive field surveys in the Hokuriku District, on the Sea of Japan side of central Honshu, Japan. This species was widely distributed over the western Hokuriku region, including the Toyama Plain, Noto Peninsula/Kaga Plain (Ishikawa Prefecture), and Fukui Plain. Analyses of mitochondrial DNA and nuclear DNA indicated that the Ishikawa and Fukui populations of Gymnogobius sp. 2, which formed a monophyletic group, were clearly divergent from other species of the G. castaneus species complex. In addition, there was a clear genetic divergence between these populations. However, the complete mtDNA replacement has occurred in the Toyama populations of Gymnogobius sp. 2, almost certainly via historical introgressive hybridization with the G. castaneus–taranetzi complex. Thus, this species forms at least three isolated lineages with unique and divergent evolutionary histories.

Behavioural interdependence in a shrimp‐goby mutualism

AbstractThe partnership between non‐burrowing gobiid fishes and alpheid shrimps is one of the most remarkable interspecific mutualisms currently recognised in behavioural biology. The shrimp rely on tactile and chemical cues from their goby partners to warn them of approaching predators. In return, the shrimp construct and maintain the burrows which provide shelter for the goby. Although aspects of this relationship have been well studied, less is known about the interdependence of the two species’ activity patterns. We conducted field observations of an obligate shrimp‐goby mutualism, Ctenogobiops feroculus and its common shrimp partner Alpheus djeddensis. We found that individual gobies were consistent in their activity levels relative to conspecifics over a 3‐day period but were not consistent in terms of the time allocated to vigilance. Both the activity and the vigilance behaviour of the goby directly correlated with the behaviour of their shrimp partners; shrimp with a more active partner were themselves more active, and visibility of the shrimp increased as vigilance time increased. By quantifying the interactions between the two species, we have gained greater insights into the mechanistic underpinnings of these complex behavioural interactions.

Functional Diversity of Evolutionary Novelties: Insights from Waterfall-Climbing Kinematics and Performance of Juvenile Gobiid Fishes.

SynopsisThe evolution of novel functional traits can contribute substantially to the diversification of lineages. Older functional traits might show greater variation than more recently evolved novelties, due to the accrual of evolutionary changes through time. However, functional complexity and many-to-one mapping of structure to function could complicate such expectations. In this context, we compared kinematics and performance across juveniles from multiple species for two styles of waterfall-climbing that are novel to gobiid fishes: ancestral “powerburst” climbing, and more recently evolved “inching”, which has been confirmed only among species of a single genus that is nested within the clade of powerburst climbers. Similar net climbing speeds across inching species seem, at first, to indicate that this more recently evolved mode of climbing exhibits less functional diversity. However, these similar net speeds arise through different pathways: Sicyopterus stimpsoni from Hawai’i move more slowly than S. lagocephalus from La Réunion, but may also spend more time moving. The production of similar performance between multiple functional pathways reflects a situation that resembles the phenomenon of many-to-one mapping of structure to function. Such similarity has the potential to mask appropriate interpretations of relative functional diversity between lineages, unless the mechanisms underlying performance are explored. More specifically, similarity in net performance between “powerburst” and “inching” styles indicates that selection on climbing performance was likely a limited factor in promoting the evolution of inching as a new mode of climbing. In this context, other processes (e.g., exaptation) might be implicated in the origin of this functional novelty.

Sperm-duct gland content increases sperm velocity in the sand goby.

ABSTRACTSperm performance is often tightly linked to male reproductive success. In many demersal gobiid fishes, the male attaches sperm embedded in a mucus produced by sperm-duct glands to the nest substrate before spawning takes place. Sperm are activated as the mucus and embedded gland content dissolve into the water. To test the importance of gland content on sperm function in Pomatoschistus minutus, a marine fish with external fertilization, we used a paired experimental design, with spermatozoa tested with and without sperm-duct gland content mixed into seawater. We measured sperm velocity, percentage of motile sperm and sperm viability over time. Sperm were found to swim 7.3% faster when gland content was mixed in the seawater. Percentage motile sperm was unaffected by the gland content. Sperm viability in seawater exceeded 24 h, but was unaffected by the gland content. An increase in sperm velocity of similar magnitude as found here has been shown by others to increase fertilization success. Since velocity-boosting properties of sperm-duct gland content have now been found in three distantly related goby species, this trait appears to be conserved across the Gobiidae family and may aid in reproduction across a range of species and environments.This article has an associated First Person interview with the first author of the paper.