The Taxonomy Tangent

Continuing from Friday, more on the fishes’ mouth! 

Open wide!

So a quick review: we know that there are some basic mouth styles: terminal (at the end of the mouth- a typical fish mouth), superior (pointed upward), inferior (pointed downward) and some fish have specialized mouths for different food preferences.  What does this mean for the fly angler?  A whole lot actually!

Grannoms galore!

Spring sucker

So it is early in the year and the suckers are kicking around in big numbers getting ready to spawn or even in the act of spawning. Being an open minded angler (you are open minded enough to read my blog so I am hoping you are open minded enough to target suckers when they are present- right?) you think to yourself, how do I target these fish? You notice that there are tons of Mother’s Day caddis kicking around (aka the Grannom or Brachycentrus to be exact- the warm water guy knows a bit about bugs- cool huh?). There are literally thousands of adults on the rocks and in the afternoon they are in the water. After reading this weird blog about fly fishing and geeking out on fish you know that the suckers you are seeing have inferior mouths. This explains why they aren’t jumping up on the surface to take the adults there. But they are moving around on the bottom. You then put on a caddis soft hackle (green body with a brown/grey hackle) with a couple of shot a foot ahead of it or you put that fly as the dropper behind a heavily weighted bugger to get it down. Within a couple of minutes you are into a nice 5 lb redhorse that goes airborne several times.
 

Banded Killi- look out, I am coming!

See, learning that the sucker family has an inferior mouth actually helped you choose the fly that caught the fish. While I have caught a few suckers on dries- truly a rare event, but it does happen- the vast majority have been caught with flies right on the bottom. They don’t often move much up the water column to take a fly. Their mouth doesn’t make it easy for them to feed anywhere but on the bottom. And having a nice fleshy set of lips makes it really easy to get a hook set. Conversely, when I go down to the Amazon and have a chance to target arowana I won’t be using heavily weighted flies. Dahlberg Divers all the way man! Their mouth is in the superior position. They probably won’t be overly interested in critters crawling around on the bottom. Knowing your target species mouth style does make a difference. I used the arowana as an example here because the only fish in Vermont that I can think of that has a good superior mouth is the banded killifish (Fundulus diaphanous). Until I can get a 000 weight rod with 10X tippet and size 32 flies, I probably won’t target them. Probably… but I am now considering it… look for the killifish post this coming summer!
 

As I have said before, the majority of fishes have a terminal mouth. It should come as no surprise that not all terminal mouths are alike. There are a wide variety of shapes and functions (which also holds true for inferior and superior mouths as well, but I want to geek out on the terminal mouth). Before I get into that too much, let’s get into a few things about fish evolution and taxonomy. It is a pretty important part of the mouth story….
 
The Fishes are in Phylum Chordata (animals with backbones, although there are some invertebrates that are Chordates, but that is another kettle of fish – pun intended), in the sub division Craniata (animals with skulls). The Class Pisces that used to encompass all the fishes is no longer used. Yea, confusing, but that can be science at times because as we learn more about the world we live in, we re-examine earlier thoughts and refine them using new data. Pretty cool really.  Alright, from there we have three SuperClasses of fishes:
 

Hagfish- purdy ain't it?

SuperClass Agnatha, the Jawless Fishes. Skeleton but no jaw. Lampreys and hagfishes are in this group. While I have caught a few salmon with lamprey still on them I have yet to make a “salmon fly” to catch the lamprey itself. These guys are not that important to us in this conversation (although the lampreys have very cool mouths and might come back in at some point).
 

Chimera- Charismatic Cartilagenous Critter

SuperClass Chondrichthyes, the Cartilaginous Fishes. These guys have a skeleton made of cartilage and have jaws. Sharks, rays, skates (no you can’t play hockey on these fish), and the chimera (I would love to find someone that has caught a chimera on a fly, but it is highly unlikely since they live at a depth of 200m or deeper). I definitely want to catch sharks on a fly at some point, but for now these guys are going to be out of the discussion. They might come back in at some point though.
 

Who doesn't love Ray Troll?

SuperClass Osteichthyes, the Bony Fishes. This is what we are talking about! These are the “modern fishes” which have a bony skeleton and a jaw. Almost all fishes that we target with a fly rod are members of this group, the only exceptions being sharks. Let’s break Osteichthyes down even further:
 
Class Sarcopterygii, the Lobe-Finned Fishes. To simplify these fish have a fleshy lobe that their fins come out of. There aren’t a whole lot of extant (currently living) fishes in this class. Lungfishes (only found in South America, Africa and Australia- super cool fish I would love to catch…) and the Coelacanth (two species of living fossil). They won’t be part of this discussion but since amphibians evolved from them, then came reptiles until eventually came the mammals then us. Gotta love us Tetrapods! In a way we owe the whole sport of fly fishing to our lobe finned ancestors. Think of it as fishing thanks to fish.
 

Big sturgeon.. Can I get that in Fly please?

Class Actinopterygii, the Ray Finned Fishes. Alright, lets break this class down.
Subclass Chondrostei, the sturgeons and bichirs. Cool fish that have skeletons that are primarily cartilage but have some ossification (bone development). Not frequently caught on flies, although the Beluga sturgeon is reputedly quite a predator….
 

Amia calva- Holostei bruiser

Subclass Holostei, my personal buddies the bowfin and gars. These are pretty primitive fishes that a select few intrepid anglers choose to target with flies. They have some mouths that are pretty interesting and will be part of our discussion.
 
Subclass Teleostei, the most diverse group of fishes alive today! Almost all fish that are typically fly fished for are in this group. These guys have mouths that are of critical importance to us. Most of the next discussion will be all about their oral adaptations! 
 

A little Teleost diversity from the Amazon

Ok, that is a whole lot of science for one day for everyone. I am sure I lost a few people somewhere along the way. Maybe I can figure out how to make a horn go off somewhere halfway through all the science. But hey, as anglers I think it is good to be aware of what fish are all about. Part of that is learning the science behind them. Having a better understanding of what fish are separates an angler from a fisherman.

Next topic- the pucker… yes, seriously, the pucker…. Stay tuned!