Cryptocentrus steinhardti (Actinopterygii; Gobiidae): a new species of shrimp-goby, and a new invasive to the Mediterranean Sea

A new species of shrimp-goby was collected at depths of 60–80 m off the southern Israeli Mediterranean coast. A unique ‘DNA barcoding’ signature (mtDNA COI and Cytb) revealed that it differs from any other previously bar-coded goby species clustered phylogenetically with the shrimp-gobies group, in which Cryptocentrus is the most speciose genus. A morphological study supported the assignment of the fish to Cryptocentrus and differentiated the new species from its congeners. The species is described here as Cryptocentrus steinhardti n. sp. However, the present phylogenetic analysis demonstrates a paraphyly of Cryptocentrus and emphasizes the need for revision of the genus based on integrating morphological and genetic characteristics. This finding constitutes the third record of an invasive shrimp goby in the Mediterranean Sea. An intriguing ecological issue arises regarding the possible formation of a fish-shrimp symbiosis in a newly invaded territory. Describing an alien tropical species in the Mediterranean prior to its discovery in native distribution is an unusual event, although not the first such case. Several similar examples are provided in the present article.

Length–weight relations of 11 goby species (Actinopterygii: Gobiiformes) from mangroves along the Ba Lat estuary of the Red River, Vietnam

Presently reported study examined the length–weight relations for 11 goby species collected from a mangrove estuary of the Red River, Vietnam. A total of 1097 individuals of the following species, representing three goby families, were analyzed: Butis butis (Hamilton, 1822); Butis koilomatodon (Bleeker, 1849); Acentrogobius moloanus (Herre, 1927); Acentrogobius viridipunctatus (Valenciennes, 1837); Apocryptodon madurensis (Bleeker, 1849); Aulopareia unicolor (Valenciennes, 1837); Glossogobius giuris (Hamilton, 1822); Gobiopsis macrostoma Steindachner, 1861; Mugilogobius abei (Jordan et Snyder, 1901); Tridentiger barbatus (Günther, 1861); and Tridentiger trigonocephalus (Gill, 1859). The regression slope values (b) ranged from 2.909 to 3.621. The majority of species had positive allometric or isometric growth pattern with b ≥ 3, except for only one species (G. giuris) which had a negative allometric growth with b = 2.909. This study provided the first LWR information of four gobies that have not been reported in FishBase yet. Besides, the reference for LWRs of other gobies at an ecologically important area like Ba Lat Estuary is also provided.

Length–weight relations of 11 goby species (Actinopterygii: Gobiiformes) from mangroves along the Ba Lat estuary of the Red River, Vietnam

Presently reported study examined the length–weight relations for 11 goby species collected from a mangrove estuary of the Red River, Vietnam. A total of 1097 individuals of the following species, representing three goby families, were analyzed: Butis butis (Hamilton, 1822); Butis koilomatodon (Bleeker, 1849); Acentrogobius moloanus (Herre, 1927); Acentrogobius viridipunctatus (Valenciennes, 1837); Apocryptodon madurensis (Bleeker, 1849); Aulopareia unicolor (Valenciennes, 1837); Glossogobius giuris (Hamilton, 1822); Gobiopsis macrostoma Steindachner, 1861; Mugilogobius abei (Jordan et Snyder, 1901); Tridentiger barbatus (Günther, 1861); and Tridentiger trigonocephalus (Gill, 1859). The regression slope values (b) ranged from 2.909 to 3.621. The majority of species had positive allometric or isometric growth pattern with b ≥ 3, except for only one species (G. giuris) which had a negative allometric growth with b = 2.909. This study provided the first LWR information of four gobies that have not been reported in FishBase yet. Besides, the reference for LWRs of other gobies at an ecologically important area like Ba Lat Estuary is also provided.

Uneven declines between corals and cryptobenthic fish symbionts from multiple disturbances

With the onset and increasing frequency of multiple disturbances, the recovery potential of critical ecosystem-building species and their mutual symbionts is threatened. Similar effects to both hosts and their symbionts following disturbances have been assumed. However, we report unequal declines between hosts and symbionts throughout multiple climate-driven disturbances in reef-building Acropora corals and cryptobenthic coral-dwelling Gobiodon gobies. Communities were surveyed before and after consecutive cyclones (2014, 2015) and heatwaves (2016, 2017). After cyclones, coral diameter and goby group size (i.e., the number of gobies within each coral) decreased similarly by 28–30%. After heatwave-induced bleaching, coral diameter decreased substantially (47%) and gobies mostly inhabited corals singly. Despite several coral species persisting after bleaching, all goby species declined, leaving 78% of corals uninhabited. These findings suggest that gobies, which are important mutual symbionts for corals, are unable to cope with consecutive disturbances. This disproportionate decline could lead to ecosystem-level disruptions through loss of key symbiont services to corals.

Uneven declines between corals and cryptobenthic fish symbionts from multiple disturbances

ABSTRACTWith the onset and increasing frequency of multiple disturbances, the recovery potential of critical ecosystem-building species and their mutual symbionts is threatened. Similar effects to both hosts and their symbionts following disturbances have been assumed. However, we report unequal declines between hosts and symbionts throughout multiple climate-driven disturbances in reef-building Acropora corals and cryptobenthic coral-dwelling Gobiodon gobies. Communities were surveyed before and after consecutive cyclones (2014, 2015) and heatwaves (2016, 2017). After cyclones, coral size and goby group size decreased similarly by 28-30%. After heatwave-induced bleaching, coral size decreased substantially (47%) and the few gobies recorded mostly inhabited corals singly. Despite several coral species still occurring after bleaching, all goby species declined, leaving 78% of corals uninhabited. These findings suggest that gobies, which are important mutual symbionts for corals, are unable to cope with consecutive disturbances. This disproportionate decline could lead to ecosystem-level disruptions through loss of key symbiotic services to corals.

FIRST DATA OF GOBY FISH IN TIEN HAI WETLAND NATURE RESERVE, THAI BINH PROVINCE

Gobiiformes is the second diverse order of fish, with more than 2000 species in the world, and 99 species in Vietnam. Many of them are commercially economic important. To understand goby fish diversity in a mangrove forest, three surveys were conducted in March, July, and August 2019 from Tien Hai Wetland Nature Reserve, Thai Binh Province. Based on morphology, a total of 25 species in 3 families of goby fish were determined in the study area. Of which, one is an endangered species (Bostrychus sinensis) as the CR category, and a number of new records were found, including one species for Vietnam (Wuhanlinigobius polylepsis), 5 species for northern Vietnam, and 9 species for the study area. Regarding the distribution pattern, the fauna from the study area shared much with those from others where mangroves and estuaries present, implying the importance of these ecosystems for goby fish. Furthermore, the maximum number of these shared goby species is 16, showing a diverse and unique characteristic of this fauna. These findings will be important information for further fish diversity conservation and fisheries exploitation in the study area.

Identification of past and present gobies: distinguishing Gobius and Pomatoschistus (Teleostei: Gobioidei) species using characters of otoliths, meristics and body morphometry

Gobies (Gobiidae + Oxudercidae) are among the largest groups of extant marine fishes. Fossils of gobies are abundant since the Miocene, and many species have been reported so far. However, delimitation of fossil goby species is challenging because molecular markers and diagnostic traits such as the disposition of sensory head papillae are lost. This study provides, for the first time, an actualistic framework for the identification of fossil goby species. We focus on characters that can in principle be recognized in fossils, and evaluate their ability to discriminate between extant goby species based on statistical analyses. Using 14 extant species of Gobius and seven species of Pomatoschistus, we conducted otolith morphometry, elliptic Fourier shape analysis of otoliths using the package ‘Momocs’, conventional fish morphometry, and meristic counts. In addition, the otoliths of all species are depicted based on SEM images and briefly described. Otolith Fourier shape analysis proved to be most efficient in discrimination of species within both genera, Gobius and Pomatoschistus. Several characters used in the other approaches also worked well, but the results were variable, and the relative taxonomic significance of particular variables tended to change depending on the species under consideration. We propose otolith shape analysis as a powerful tool to explore ancient goby species diversity when samples with abundant fossil otoliths are present. Overall, the herein presented data will greatly facilitate delimitation of fossil goby species in future studies, and will consequently shed new light on the evolution of goby diversity and biogeography through time.

IDENTIFICATION OF FRESHWATER GOBY SPECIES FROM THE BIAK AND KOYOAN RIVERS, LUWUK BANGGAI, CENTRAL SULAWESI

Sulawesi is an island famous for its biodiversity, including many endemic species. In particular, Sulawesi has the highest number of gobies in the world, including species with potential as food and/or ornamental fishes. The exploration of freshwater ichthyofauna is important in the context of Indonesian and global biodiversity. This research aimed to identify gobies found in the Luwuk Banggai area of Central Sulawesi, as a contribution to the exploration of Indonesian ichthyofaunal biodiversity. Gobies were sampled from January to March 2019 in the Biak and Koyoan Rivers. The sampled fish were measured and identified based on morphological characteristics. A total of 52 specimens were collected, and identified as belonging to 17 species within two families, the Gobiidae and Eleotridae. Gobies from the Koyoan River comprised 32 specimens from 8 species, while 20 specimens belonging to species were found in the Biak River. Only two species were found in both rivers: Stiphodon semoni and Sicyopterus lagocephalus. These results augment the body of knowledge regarding the presence and distribution of gobies in Indonesia