A major goal of the aquaculture industry is to reduce collection pressure on wild populations by developing captive breeding techniques for marine ornamental species, particularly coral reef fishes. ...The objective of this study was to develop a rearing protocol for two recently described species of neon gobies that are endemic to the Mesoamerican Barrier Reef: 1) Elacatinus lori; and 2) Elacatinus colini. First, the current study describes the reproductive behavior and larval development of both species. Second, it evaluates the effects of different rotifer and Artemia densities on the survival and growth of E. lori and E. colini larvae. Third, it compares the survival and growth of E. colini larvae fed wild plankton to those fed a combination of rotifers and Artemia. Once acclimated, pairs of E. lori began spawning in 53.2±12.4 d (mean±sd), while pairs of E. colini took only 12.2±10.3 d. E. lori produced more embryos per clutch (1009±477) than E. colini (168±83). E. lori larvae hatched 8.18±0.4days after initial observation with a notochord length of 3.67±0.2mm. In comparison, E. colini larvae hatched 6.8±0.4days after initial observation with a notochord length of 3.51±2.3mm. Both species settled as early as 28days post hatch at 9–9.5mm standard length, following the fusion of the pelvic fins to form a pelvic disc. During rotifer density trials, from 0 to 6days post hatch, there was no significant difference in survival or standard length between treatments fed 10, 15 or 20rotifersml−1 for either species. During Artemia density trials, from 6 to 14days post hatch, control treatments fed solely on 15rotifersml−1 had significantly higher survival than treatments that were fed rotifers in combination with 3, 6 or 9Artemiaml−1. Finally, E. colini larvae that were fed wild plankton had significantly higher survival and growth than those fed with a combination of 15rotifersml−1 and 3Artemiaml−1. The results of this study suggest that Artemia nauplii are not a suitable prey for E. lori or E. colini larvae. Our results demonstrate the feasibility of rearing E. lori and E. colini to settlement, and suggest that 10–20rotifersml−1 and wild plankton provide a viable starting point for optimizing the survival and growth of Elacatinus spp. larvae.
•A description of reproductive behavior and a larval rearing protocol are provided for two species of Elacatinus gobies.•There was no difference in the survival or standard length of larvae that were fed 10, 15 or 20rotifers ml−1.•Larvae fed Artemia beginning at 6days post hatch had lower survival than controls fed solely with rotifers.•E. colini larvae fed wild plankton had higher survival and growth than those fed a combination of rotifers and Artemia.•A diet of 10 – 20rotifers ml−1 and wild plankton provides a viable starting point for rearing Elacatinus spp. larvae.
•CTMax was tested for 35 coastal species.•Tropical and temperate crabs, shrimp and fish were used.•Warming tolerance was higher for temperate species.•Acclimation capacity was higher for temperate ...species.•Tropical species seem to be more vulnerable to further climate warming.
Ecological forecasting on the likely impacts of climate warming is crucial at a time when several ecosystems seem to be responding to this environmental threat. Among the most important questions are: which are the most vulnerable organisms to climate warming and where are they? Recently, there has been debate on whether the tropics or temperate zones are more vulnerable to warming. Vulnerability toward higher temperatures will depend on the organisms’ thermal limits and also on their acclimation capacity, which remains largely unknown for most species. The aim of the present work was to estimate (1) the upper thermal limits (Critical Thermal Maximum (CTMax)), (2) the warming tolerance (CTMax – Maximum Habitat Temperature) and (3) the acclimation capacity of tropical and temperate rocky shore organisms. Differences in biological groups (decapod crustaceans vs fish) were investigated and the effect of region (tropical vs temperate) and habitat (intertidal vs subtidal) was tested. Overall, 35 species were tested. For the assessment of the acclimation capacity, tropical-temperate pairs of closely related species of shrimp, crab and fish were selected. Warming tolerance was higher for temperate species than for tropical species and higher for subtidal species than for intertidal species, confirming that species with the highest thermal limits have the lowest warming tolerance. All species tested presented some acclimation capacity (CTMaxTrial−CTMaxControl), with the exception of gobiid fish, which was not observed to acclimate. The tropical species tested showed a lower acclimation capacity than their temperate counterparts. Given that tropical rocky shore organisms are already living very close to their thermal limits and that their acclimation capacity is limited, it is likely that the impacts of global warming will be evident sooner in the tropics than in the temperate zone.
A checklist of 73 gobiid species (Teleostei: Gobiidae) recorded to date from the Mediterranean Sea is established following the evidence approach for checklists. The Mediterranean gobiofauna ...currently has 62 known native species and 11 alien species. An identification key to gobiid species known from the area is provided. The principles of character selection for the key are discussed.
Live corals are the key habitat forming organisms on coral reefs, contributing to both biological and physical structure. Understanding the importance of corals for reef fishes is, however, ...restricted to a few key families of fishes, whereas it is likely that a vast number of fish species will be adversely affected by the loss of live corals. This study used data from published literature together with independent field based surveys to quantify the range of reef fish species that use live coral habitats. A total of 320 species from 39 families use live coral habitats, accounting for approximately 8 % of all reef fishes. Many of the fishes reported to use live corals are from the families Pomacentridae (68 spp.) and Gobiidae (44 spp.) and most (66 %) are either planktivores or omnivores. 126 species of fish associate with corals as juveniles, although many of these fishes have no apparent affiliation with coral as adults, suggesting an ontogenetic shift in coral reliance. Collectively, reef fishes have been reported to use at least 93 species of coral, mainly from the genus Acropora and Porities and associate predominantly with branching growth forms. Some fish associate with a single coral species, whilst others can be found on more than 20 different species of coral indicating there is considerable variation in habitat specialisation among coral associated fish species. The large number of fishes that rely on coral highlights that habitat degradation and coral loss will have significant consequences for biodiversity and productivity of reef fish assemblages.
Five Gobiid fish species have recently increased their ranges along the Danube/Rhine river corridor. Studies to date, however, have tended to be local, site specific and reactive, examining just one ...or few species. As such, overall range has tended to be assumed based on a summary of patchy, and sometimes contradictory, data. This study provides an up-to-date literature review of first records of occurrence for all five species along their expansion route. In addition, available shipping data are examined to identify possible proximal causes of introduction. Three main discontinuous population centres were identified; all at or near important container ports: Vienna, Duisburg and Rotterdam. Shipping is confirmed as an important factor in the rapid national and international expansion of Ponto-Caspian Gobiids, with downstream drift, rip-rap and heavy boat traffic contributing to rapid spread on the Rhine. Geopolitical factors, however, such as the fall of communism and the Balkan conflict, have been key in influencing where, when, and by which route gobies first appear. Rapid expansion of Gobiids in the Rhine raises the possibility of establishment throughout mainland Europe via two new potential invasion corridors across Germany/Poland and France.Original Abstract: Cinq especes de poissons Gobiidae ont recemment etendu leurs repartitions dans le corridor Danube/Rhin. Les etudes menees a ce jour ont cependant tendance a etre locales, specifiques au site, et n'examinent seulement qu'une ou quelques especes. De ce fait, la repartition globale a tendance a etre evaluee sur la base d'un resume de donnees fragmentaires et parfois contradictoires. Cette etude est une synthese de la litterature des premiers signalements de presence pour les cinq especes le long de leur itineraire d'expansion. En outre, les donnees de navigation disponibles sont examinees afin de determiner les causes proximales possibles d'introduction. Trois principaux centres de population disjoints ont ete identifies, tous dans ou pres des ports a conteneurs importants : Vienne, Duisbourg et Rotterdam. La navigation est confirmee comme un facteur important dans l'expansion nationale et internationale rapide des Gobiidae pontocaspiens, avec une derive vers l'aval; les enrochements et la circulation de gros bateaux contribuant a la propagation rapide sur le Rhin. Des facteurs geopolitiques, cependant, comme la chute du communisme et le conflit des Balkans, ont joue un role cle en influencant ou, quand et par quelle voie les gobies apparaissent en premier. L'expansion rapide des Gobiidae dans le Rhin souleve la possibilite d'implantation dans toute l'Europe continentale via deux nouveaux corridors d'invasion potentiels a travers l'Allemagne/Pologne et la France.
The occurrence patterns of the larval and juvenile gluttonous goby, Chaenogobius gulosus in Omori Furusato-no-Hamabe Park in the innermost portion of Tokyo Bay were investigated by monthly sampling. ...Four types of gear were used: a small seine net towed off the sandybeach and over the tidal flat between January 2015 and December 2018; basket nets placed at awharf with a vertical seawall between January 2016 and December 2018; a hand net used at thewharf between January 2016 and December 2016; and a set net placed on the tidal flat and in thewaterway from the tidal flat to a tidepool between January 2016 and December 2018. Ontogenetic intervals were determined from the morphometric characters of 274 specimens（3.93-41.7 mmbody length［BL］）and the osteological characters of 92 cleared and stained specimens（3.93-25.5 mm BL）. In total, 124 individuals（3.78-30.3 mm BL）were collected from the sandy beach, 447（3.98-72.9 mm BL）from the tidal flat, 239（22.8-107 mm BL）from the wharf using basket nets,221（6.30-45.2 mm BL）from the wharf using a hand net, two（17.3 and 30.4 mm BL）from thetidal flat using a set net, and one（4.50 mm BL）from the waterway. Based on morphological development, the developmental stages of the larvae and juveniles were divided into four phaseseach of swimming and feeding functions and five phases of relative growth. The occurrence patterns and ontogenetic intervals imply that hatched larvae are transferred to the sandy beach ortidal flat by flow, occupy these habitats while their swimming and feeding functions develop,then begin migrating to the wharf at 8-9 mm BL. Subsequently, juveniles settle on the seafloor;they then migrate and settle at the wharf until ~35 mm BL. C. gulosus utilizes different habitatsin this artificially established seaside zone depending on the developmental phase from hatchingto immature individuals, although the distribution of mature individuals remains unclear.
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•Extensive sampling of estuarine gobies around the Australian coastline.•Multiple lines of evidence for at least six cryptic species.•Major unrealized biodiversity occurs in the ...region and potentially abroad.•Diverse estuarine faunas need consideration with future development and management.
Snubnose gobies (genus Pseudogobius: Gobionellinae) are ubiquitous to, and important components of, estuarine ecosystems of the Indo-west Pacific. These small benthic fishes occur in freshwater, brackish and marine habitats such as mangroves, sheltered tide pools and lowland streams, and represent a model group for understanding the biodiversity and biogeography of estuarine fauna. To develop the species-level framework required for a concurrent morphological taxonomic appraisal, we undertook thorough sampling around the extensive Australian coastline, referenced to international locations, as part of a molecular systematic review using both nuclear and mitochondrial markers. The results indicate that while there are currently eight recognised species, the true diversity is close to double this, with a hotspot of endemism located in Australia. Complicated patterns were observed in southern Australia owing to two differing zones of introgression/admixture. Key drivers of diversity in the group appear to include plate tectonics, latitude, and historic barriers under glacial maxima, where an interplay between ready dispersal and habitat specialisation has led to regional panmixia but frequent geographic compartmentalisation within past and present landscapes. The findings have significant implications for biodiversity conservation, coastal and estuarine development, the basic foundations of field ecology, and for applied use such as in biomonitoring.
Parasites have deleterious effects on their hosts, often resulting in altered host behavior or increased energy expenditure. When organisms are exposed to suboptimal environments, parasite loading ...may increase. Microbialite pools along the warm temperate South African coastline have been hypothesized as refugia for Epaulette gobies (Coryogalops sordidus, Gobiidae) when they are outside of their previously known subtropical distribution. The aim of this study was to determine if C. sordidus individuals infected with metacercarial cysts display higher metabolic rates or different swimming behavior compared to noninfected individuals. We measured each goby's swimming performance using a critical station‐holding speed (Ucrit) test (n = 60) and visually scored their swimming behavior (n = 52) during these measurements. Also, we measured the metabolic rate of gobies using an intermittent flow respirometer system to determine standard metabolic rate (SMR) and maximum metabolic rate (MMR) from gobies at 21°C before and after swimming trials. Metacercarial load carried by infected gobies seemingly had no impact on the host's energetics (SMR or MMR), swimming ability (as repeated Ucrit tests), or swimming behavior compared to noninfected gobies. Thus, the metacercarial intensity observed in gobies in the current study appeared to have no impact on host swimming performance or behavior. Furthermore, the swimming capacity observed for C. sordidus, in general, suggests that this goby is a poor swimmer compared to other gobiid species.
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