Geology topics

Brendan C. Ebner

Publications and source records attributed to Brendan C. Ebner.

3 recordsLinked to original sources

USGS2026

Adult sicydiine gobies visually communicate via a spectacular array of signals, ornaments, and behaviours

Arguably, the most striking aspect of rock-climbing gobies of the subfamily Sicydiinae is their display of colour. Conversely, the taxonomy, biogeography, and migratory aspects of sicydiine biology have progressed much more than has the science of their visual communication and behaviour. Here, we form a virtual team to consolidate and offer our collective experiences in observing sicydiines across many islands, countries, and continental margins, primarily focusing on intraspecific interactions. We provide a framework of visible morphological features of male and female fish, along with natural history commentary, and make preliminary interpretations of the behaviours, their functions, and the circumstances that appear to underlie different types of visual communication by these gobies. We also make use of learning from both (a) studies of sicydiine evolution and ecology where it relates to in-stream migration and predation, and (b) visual communication science which has been derived from studies of other taxa including coral reef fishes ( e.g., wrasses, goatfishes) and model freshwater fish groups such as cichlids, darters, guppies and sticklebacks to interpret some of what we have observed sicydiines doing in streams. We then identify priorities for research and management, contending that this group of fishes represents a very promising model animal group for enhancing understanding of animal visual communication. Whilst tropical streams face a range of threatening processes, sicydiine gobies specifically, are additionally vulnerable to overharvest for the aquarium trade as a function of their attractiveness and spectacular visual displays. The latter is a matter of global conservation relevance.

Cybium↗

USGS2025

Blueprints for riverine cod nest boxes draw from multiple design considerations

Designing aquatic nest boxes is rarely afforded detailed scientific account. Here we provide some historical context for nest boxes used in production of large-bodied fishes of the Australian freshwater cod genus Maccullochella . Our experience with eastern freshwater cod is used as a case study to: (a) convey aspects of the complexity of the nest box design process and to (b) demonstrate the importance of visual literacy in project communication across the variety of contributors to the eco-design process. Specifically, we describe a new, two-variant, triangular nest box design for application in rivers and modifications to a standard stainless steel nest box for hatchery-pond-based spawning of eastern freshwater cod M. ikei . We designed the boxes to test adult preference for single versus double entrance/exits to cavities in hatchery and field environments. An important consideration specific to hatchery production is harvesting demersal, adhesive eggs prior to hatching to minimise fungal infection of eggs and physical loss of larvae, in addition to providing critical first feeding of larvae. In contrast, field nest box design incorporated multiple factors and associated trade-offs related to both internal and external design, ranging from manufacturer capability, material types, cost, transportability, hydrological performance, biodegradability, retrievability, as well as biological and ecological function. Only preliminary findings from field nest box deployments are provided here, and we focus primarily on elements of visual language in the form of conceptual drawings, sketches and final schematics which have been central to our process. We emphasise the benefit of harnessing input from multiple fields of expertise and documenting and testing designs of nest boxes for cavity nesting fishes, under both controlled hatchery and more complex field conditions.

Aquaculture, Fish and Fisheries↗

USGS2013

Tracking animals in freshwater with electronic tags: past, present and future

Considerable technical developments over the past half century have enabled widespread application of electronic tags to the study of animals in the wild, including in freshwater environments. We review the constraints associated with freshwater telemetry and biologging and the technical developments relevant to their use. Technical constraints for tracking animals are often influenced by the characteristics of the animals being studied and the environment they inhabit. Collectively, they influence which and how technologies can be used and their relative effectiveness. Although radio telemetry has historically been the most commonly used technology in freshwater, passive integrated transponder (PIT) technology, acoustic telemetry and biologgers are becoming more popular. Most telemetry studies have focused on fish, although an increasing number have focused on other taxa, such as turtles, crustaceans and molluscs. Key technical developments for freshwater systems include: miniaturization of tags for tracking small-size life stages and species, fixed stations and coded tags for tracking large samples of animals over long distances and large temporal scales, inexpensive PIT systems that enable mass tagging to yield population- and community-level relevant sample sizes, incorporation of sensors into electronic tags, validation of tag attachment procedures with a focus on maintaining animal welfare, incorporation of different techniques (for example, genetics, stable isotopes) and peripheral technologies (for example, geographic information systems, hydroacoustics), development of novel analytical techniques, and extensive international collaboration. Innovations are still needed in tag miniaturization, data analysis and visualization, and in tracking animals over larger spatial scales (for example, pelagic areas of lakes) and in challenging environments (for example, large dynamic floodplain systems, under ice). There seems to be a particular need for adapting various global positioning system and satellite tagging approaches to freshwater. Electronic tagging provides a mechanism to collect detailed information from imperilled animals and species that have no direct economic value. Current and future advances will continue to improve our knowledge of the natural history of aquatic animals and ecological processes in freshwater ecosystems while facilitating evidence-based resource management and conservation.

Animal Biotelemetry↗