Identifying a fish

Australasian Fishes is closing in on its 50,000th observation. Of those, more than 95% have been identified to species by more than 1400 people. This is an extraordinary effort; thank you all!

Why, you might ask, aren’t they all identified to species? There are a number of answers to that question, more than one of which may apply to a single observation.

Let’s start with a couple of obvious reasons, image quality and size of the fish in the image. If the photo is poor, or the fish only occupies a tiny part of the image, it may be difficult to see the diagnostic features. In addition, the angle at which the photo is taken sometimes results in diagnostic features not being visible.

For some observations, the shape and colour pattern of the fish may not be enough to identify it. In the case of beach washups, the colour pattern of the fish may be lost entirely. Sometimes, the photo may be fine but closeups are required. In other cases, counts of fin elements, gill rakers or even internal morphology is required to make an accurate identification. And don’t get me started on identifying hybrids! Of course, the fish faunas of Australia and New Zealand aren’t fully discovered. Sometimes observations of potential new species are uploaded, such as the two above.

So well done everyone! Who would have thought when the project started in October 2016, that in less than 2.5 years we’d be looking at nearly 50,000 observations, the majority of which are identified to species.