Ray-finned fishes are the most diverse vertebrate taxon, yet they seem to be one of the less frequently observed. There are exceptions – popular snorkeling and scuba destinations such as Aruba have abundant observations of reef fishes, and there are currently 8 pages of observations of billfishes (the Sailfish, three species of Spearfish, and four of Marlins), all clearly in sportfishing situations. These seem to be the exceptions that prove the rule, however; the great majority of ray-finned fishes, those which neither live on coral reefs nor are sought after as game fish, appear to be rarely observed.
To test this hypothesis, I checked the “species” tab for vertebrate observations in Iowa. The first fish did not appear until number 47, and it was a game fish, Bluegill. The second was number 66, another game fish, the Largemouth Bass. Next was Green Sunfish at number 82, then Carp at number 129.
The same procedure for Pittsburgh. This time the first fish did not appear until number 115, and it was again the Bluegill. Sacramento River: the Chinook Salmon, around number 127 (and the Bluegill five species later).
Finally, to see whether this bias extended beyond the United States, I tried Burgundy, France. The first fish to appear was the Northern Pike at number 117 – 32 observations, as compared with 494 observations of the number one species, the Common Wall Lizard.
It can’t be because of inaccessibility – the plethora of underwater observations of coral reef life shows that many iNat users have the equipment for this, and more of us live near freshwater streams than coral reefs. My hunch is that it is a lack of interest; that an iNatter with underwater gear is more likely to be interested in using it in oceans and seas. Snorkeling and scuba diving – and sportfishing – are more socially acceptable than donning a mask and lying prone in a stream less than a foot deep.
Look at what a difference it makes. Standing in a stream and photographing the fish from above will give results like this:
The minnows in a picture like this will never be identified beyond “Ray-finned Fishes.” However, by getting down to a fish’s eye view (never mind the social awkwardness), that same group of minnows looks like this:
The video I shot is even better! Now these can be identified as Ironcolor Shiners, a widespread species on the Coastal Plain, but only sporadically observed. This particular stream, Green Mill Run in Greenville, North Carolina, is popular with fossil hunters; on any given weekend in the warm season, there will be groups of them sifting through the gravel. This species of minnow is the most easily seen animal life in the stream. Yet – once again – I have made the first observation for Pitt County and one of only 5 in all of North Carolina.
I’m sure that not all of you have underwater gear. But for those of you who do, you don’t need to travel to the Great Barrier Reef to make underwater observations. What about the diversity in the “insignificant” streams and creeks close to home?
