A comprehensive analysis of all known fishes from Sydney Harbour.

Fishes represent an important natural resource and yet their diversity and function in dynamic estuaries with relatively high levels of human pressure such as Sydney Harbour have rarely been quantified. Further, Eastern Australia supports the survival and persistence of an increasing number of tropical species found within temperate estuaries owing to increasing average ocean temperatures. A re-valuation of the number of fish species known from Sydney Harbour is therefore needed. In this study, we generated an up-to-date and annotated checklist of fishes recorded from Sydney Harbour based on verified natural history records as well as newly available citizen science records based on opportunistic observations and structured surveys. We explored the spatial and temporal distribution of these records. In addition, we quantified the function, conservation status, and commercial importance of the identified fishes. The number of fish species recorded from Sydney Harbour now stands at 675, an increase of 89 species (15 %) when compared to the most recent evaluation in 2013. We attribute this increase in fish diversity over a relatively short time to the contribution of newer citizen science programs as well as the influx and survival of fishes in the Harbour with preferences for warmer waters. Some fish families were also overrepresented in the more urbanized and polluted sections of the Harbour. In forecasting further environmental impacts on the fishes of Sydney Harbour, we recommend increased integration of collaborative citizen science programs and natural history collections as a means to track these changes.

The use of environmental DNA to monitor impacted coastal estuaries.

Environmental DNA (eDNA) metabarcoding is increasingly being used to assess community composition in coastal ecosystems. In this study, we chose to examine temporal and spatial changes in the aquatic community of Manly Lagoon - one of the most heavily developed and polluted estuaries in eastern Australia. Based on metabarcoding of the 16S mitochondrial gene (for fish) and the 18S nuclear gene (for macroinvertebrates), we identified seasonal differences in fish and macroinvertebrate community composition as well as species richness, which correlated, in some cases, with the environmental parameters of sea surface temperature and freshwater input. Moreover, given the greater taxonomic resolution of fish versus macroinvertebrate assignments, we identified several known migratory fish species of management importance that contributed significantly to the overall patterns observed. Overall, our data support the use of eDNA metabarcoding to track fish assemblages shifting in response to environmental drivers in polluted estuaries with increased sampling and consultation with historical data.

A preliminary review of the eastern Pacific species of Elacatinus (Perciformes: Gobiidae)

Elacatinus limbaughi is described as new from the Gulf of California. Elacatimus digueti is redescribed and Elacatinus inornatus Bussing is synonymyzed with E. digueti. Data are presented on geographical variation in Elacatinus puncticulatus and E. digueti. Species of the genus Elacatimus are normally associated with coral reefs and several of the species clean parasites from other fishes. Elacatinus is regarded as distinct from Gobiosoma, based on vertebral and other characteristics.

Revision of the eastern Pacific species of Gobulus (Perciformes: Gobiidae), with description of a new species

Gobulus birdsongi is described as a new species from the Pacific coast of Panama. The two other known species of Gobulus from the eastern Pacific, Gobulus crescentalis and G. hancocki are redescribed. Gobulus birdsongi differs from other species in the genus in having more numerous second dorsal and anal rays. Gobulus hancocki differs from G. crescentalis in having a much smaller eye. The genus is distinctive in having reversed countershading, with the ventral surface of the body darker than the dorsal surface.