A tale of two fishes
Lisa Nihill
Learning is often like going down the rabbit hole, each piece of acquired knowledge leads to more questions and sends you off down a different tunnel. I’m now itching to get back in the ocean and pay a bit more attention to these guys who become more interesting all the time.
This week I have been sending out a photographic identification quiz containing 20 photographs of both the Common and the Reticulated dragonets. The idea behind the quiz is to get an idea of an overall % error and to compare the data for identification of males versus females/juvenile males. As a biologist I fully acknowledge that photographic identification is not ideal, and certainly some of the photographs will reflect real conditions under which live recordings would be made (although you do get more time).
The development of the quiz has not been without difficulties. The initial plan was to have a bank of 100 photographs in a bank and randomly choose from this bank ensuring a balance. I had intended to obtain photographs from both the aquarium and the field, but these plans were curtailed by our collective current circumstances. This left me searching the internet for pictures where I found many which I believed to be labelled incorrectly. In fact, finding photographs which were of reputable sources was possible, but limited my bank down to a less desirable 30. Here again highlights, and possibly contributes to identification issues. With the females and the juveniles, I honestly can’t tell myself and had to double check, one was subsequently removed from the bank. Here is an example of one which I think may be mislabelled, what do you think? Common or reticulated? Can you find more?
All Seasearch members have been doing exceptionally well in the quiz so far and many have diligently pointed out to me that many times they would like a genus option, where I have provided only species choices. This is very encouraging and of course would be the correct thing to do if unsure, and unsurety is sure to happen with some of these, I ask for people to give it a go in the interest of statistically highlighting the difficulties in identification of females and juveniles.
There has been some interesting feedback on habitat preferences too with some saying that the reticulated dragonet prefers hanging out on rocky mixed ground, where trawlers do not go and therefore divers gravitate towards. There are some who say they are found in sandy, muddy areas and some who say they are mostly on mixed gravel and coarse sand. This poses another interesting question and I plan to pull the reticulated records to determine if there is a clear pattern to substrate preference.
Until next time, I appreciate any and all participation, and wait in anticipation for your insights.
If you’d like to take part in the quiz you can download the pdf here and simply answer and email to Lisanihill@gmail.com.
