Salamanders

A recent post on Facebook asking to identify a salamander got me curious as to the difference between salamanders and newts, and a little research provided some very interesting answers to several different salamander questions.

There are several families of these amphibians. There are four families of entirely aquatic salamanders, those who live their entire life cycles completely in the water and cannot live long out of the water. The most common species in Missouri are mud puppies and hellbenders (if you can call hellbenders common). Those two are in separate families, but both live their entire lives underwater. You'll never see one out of the water unless it was taken from the water, and it won't live long out of the water. The two look very different, but the biggest real difference between them is that mud puppies have external gills, feathery reddish or pinkish structures that stick out from their necks. Hellbenders have internal gills with small gill openings to let the water in and out--and oddly, one gill opening is often completely closed.

The other two families of entirely aquatic salamanders are sirens and amphiumas, both of which are long and eel-like. Sirens have ONLY forelimbs, and they are very small. Amphiumas have both fore and hind limbs, but all are very small. Both are mainly confined to ditches and swamps of Southeast Missouri, and most people will never see one.

The newt family is interesting. It is represented by only one Missouri species, the central newt. And what makes newts different is that they go through THREE life stages. There is the entirely aquatic larval stage (kinda like a tadpole is the larval stage of a frog or toad). But before turning into an adult, a newt goes through an intermediate stage where it becomes an eft, and lives entirely on land. It remains an eft for two or three years, and THEN changes to the adult stage, and moves BACK into the water, becoming entirely aquatic. So you might see an eft out of the water, but you won't see an adult newt anywhere but in the water (they prefer fishless ponds).

There are two main dry land salamander families, the mole salamanders and the lungless salamanders. The adults of both families spend most of their time in moist but not wet places, like underneath forest debris and rocks--some live in caves. They do NOT need water except as a place to lay their eggs, as the larval stage IS aquatic, like frogs and toads. Members of the mole salamander family tend to be fairly large, thick-bodied, with thick tails. As you can guess from the name, some species live much of their lives underground. But mole salamanders have lungs and breathe like we do, more or less. Lungless salamanders, as you can guess, DON'T have lungs, they take in oxygen through their skins. They tend to be small and thinner bodied with long, thin tails.

So the next time you encounter a salamander somewhere out of the water, don't assume it needs to be IN the water. They do not. Just give it a chance to get under something, or leave it alone. They don't like bright sun and will get dried out if exposed to it too long, but ordinarily all they need is shade.

Goggle-eye--the rock bass species of the Ozarks

Growing up in the Missouri Ozarks and being from a family of avid anglers, I learned the names of common fish early on...or at least the Ozark names. One of those common fish was the goggle-eye, as we called it. When I was in junior high school, finding school too easy and tending to get in trouble now and then because I was bored and had all my work done, I was sometimes given a "special" project to keep me busy, and because I was already interesting in drawing and painting, it was often something to do with those pursuits. One such project was for me to do a "book" illustrating the common fish species of Missouri, and that's when I first learned that what we called a goggle-eye was a rock bass.

At that time, back in the early 1960s, there was just one rock bass in the Ozarks--or at least all the rock bass were lumped under a single species. But sometime later, biologists discovered (or perhaps just decided) that there were a total of three rock bass species in the region, the "typical" rock bass--northern rock bass, the shadow bass, and the Ozark bass.  Shadow bass had been recognized as a separate species back in the 1930s, and was generally considered the "southern" rock bass.  But the Ozark bass wasn't recognized until 1977.  Most anglers, if they even heard about this, ignored it, because all three were pretty similar in appearance. So similar, in fact, that the average angler probably never noticed the subtle differences, or attributed them to individual variation.

  Complicating the issue was that all species of rock bass have the ability to rapidly change color and especially pattern.  This is a fairly common attribute among freshwater fish.  It is governed by cells called melanocytes.  Humans also have melanocytes; they are the skin cells that produce tanning effects.  But these fish melanocytes hold special structures called melanosomes, which contain dark pigment.  The melanosomes in each cell have the ability to contract to the center portion of the cell, or expand out to the edges of the cell.  When they expand to the edges, they turn the color of that skin cell darker.  Other basal skin cells in fish also govern color; these are called chromatophores, and operate the same way as the melanocytes, but contain various other pigments.  So the fish can rapidly become darker or lighter and have dark markings appear or disappear with the operation of the melanosomes, and change overall color or color in certain portions of the body by the chromatophores.  Whether the fish can do this voluntarily, or whether it is an automatic response to various stimuli, is an open question.  But we know that external factors such as light levels, turbidity of the water, and the character of the fish's surroundings can cause color changes, as well as internal factors like stress and excitement.  Many fish also change color (usually getting brighter or more strongly marked) during spawning season, and can rapidly change color when in the actual act of spawning.

When it comes to the rock bass species, they are masters at these color changes, especially the dark and light changes that make their markings appear, disappear, or get more or less prominent.  Thus it's difficult to attribute the shape or prominence of various markings on the fish to it being one species or another.  There are unchanging structural characteristics that are slightly different in each species, but actually, if nothing else, you can tell which species you've just caught from where you caught it, with a few exceptions. In the early days, according to many biologists who have studied them, there were NO rock bass in the Gasconade or Osage river systems (including streams like the Niangua and Big Piney) and all the rock bass in those streams come from stockings in the 1930s and 1940s.  Because those fish are the same species as Meramec River system rock bass, it's surmised that they were collected from the Meramec River or its tributaries and transplanted. 1931 was the first year that rock bass were documented in the Big Piney, and they were not documented in the Niangua until 1940, and in lower tributaries of the Osage like Tavern Creek and Maries River until 1964!

Why were there no rock bass in these two river systems, when they were found over the rest of the Ozarks?  The most likely explanation has to do with the connections between river systems.  The centers of distribution of northern rock bass are the upper Mississippi river system above the mouth of the Missouri, the Great Lakes, and the Ohio river system (which includes the Tennessee system).  It's easy to see the connection from the upper Mississippi to the Meramec, which enters the Mississippi a fairly short distance below the mouth of the Missouri.  But in order to get to the Gasconade and Osage, rock bass would have had to travel up the Missouri River a good distance.  And historically, the Missouri was one of the more turbid rivers on earth, far muddier than the upper Mississippi above the two rivers, which, although much shorter, flowed considerably more water.  Perhaps the Missouri was just too muddy and silty for rock bass, which generally live in clear water, to travel to reach the Gasconade and Osage.  But the Mississippi probably diluted the mud in the Missouri from where the two come together, making it possible for rock bass to move down it to the Meramec and the short, direct tributaries of the Mississippi downstream along the eastern border of Missouri.

As for the other two species, shadow bass are mainly a southern "model" of the rock bass.  Their center of distribution is the rivers from Mississippi to Georgia that flow south into the Gulf of Mexico; the Ozarks is actually an outlier in their range, separated from the other places they live.  But the streams in which shadow bass live in the Ozarks do have a connection to the lower Mississippi, because the shadow bass is native to tributaries on both sides of the river in Mississippi and Louisiana.  The streams where they live in the Ozarks--Castor, St. Francis, Black, and Arkansas river systems--all end up in the lower Mississippi well down into Arkansas (or at least they once did; Castor has been diverted into the Mississippi just south of Cape Girardeau, MO, by the Diversion Channel).

The Ozark bass is a bit of a special case, however.  The upper White River system, above the mouth of Black River, is the only place on earth to which it is native.  So it must have evolved in these rivers.  Why it is separate from the shadow bass, which is native to the Black river system, is a mystery, since Black River runs into White River at the edge of the Ozarks and has a clear connection to the upper White.  All these species in the Ozarks would probably have become established in their present ranges at the end of the last ice age.  Previously, even though the ice never reached the Ozarks (stopping just north of the Missouri River), the climate would have been much different and perhaps too cold to support them.  Assuming they evolved long before, there were probably sanctuaries where they remained during the cold times, such as the southern portions of the Tennessee river system for northern rock bass, and the Gulf Coast streams for the shadow bass.  But perhaps the ancestral Ozark bass remained in the upper White and tributaries during the cold climate, and had time to evolve into a different fish.

So, if you are fishing the Meramec river system (Meramec, Big, Bourbeuse, Huzzah, Courtois), Gasconade system (Gasconade, Big Piney, Osage Fork), Osage system (Niangua, Maries, Tavern), or any of the direct tributaries to the Mississippi between St. Louis and Cape Girardeau, the fish you will catch will be a northern rock bass (scientific name Ambloplites rupestris). If you are on the Castor River system (Castor, Whitewater), the St. Francis system (St. Francis, Little St. Francis, Big Creek), the Black system (Black, Current, Jacks Fork, Eleven Point), or the Arkansas system in Arkansas and Oklahoma (Big Piney Creek, Mulberry, Illinois), you're going to be catching shadow bass (Ambloplites ariommus), and if you're on the upper White River system (North Fork, Bryant, Beaver, James, Finley, and the Buffalo, Kings, and Crooked Creek in Arkansas) you will catch the species that happens to ONLY be native to that river system, the Ozark bass (Ambloplites constellatus). Only on the streams of far southwest Missouri (Elk, Big Sugar, Spring) will there be a bit of a question.  Theoretically these streams, which eventually flow into the Arkansas River by way of the Neosho and Grand rivers, should hold shadow bass.  But apparently at some point there were enough northern rock bass transplanted to them that the fish in them appear to have genetic characteristics of both species.

There is actually a fourth species of rock bass, though it is far from the Ozarks.  The Roanoke bass is native only to some drainages above the fall line in Virginia and North Carolina.

Below are scientific illustrations I've done of all three Ozark rock bass species, and descriptions of their distinguishing characteristics.  The illustrations are done from photos of these fish that I have taken of fish I've caught, and modified where necessary to more clearly show the color and structure of these fish and to include some color patterning that I've seen in other individuals.

Northern Rock Bass (Ambloplites rupestris)

This is the native species of the Meramec Basin, the Gasconade and Osage river systems, and direct tributaries of the Mississippi River between St. Louis and Cape Girardeau.  Rock bass in the streams of the southwestern corner of Missouri may also have many northern rock bass characteristics.  The main characteristic of this rock bass that distinguishes it from the shadow bass is the coloration of the anal fin.  In these northern rock bass it is almost unmarked except for a thin black margin, especially on males, while in shadow bass the anal fin is usually heavily mottled and may lack the dark margin.  The dorsal and caudal (tail) fin of northern rock bass may also have a black margin.  Other than that, northern rock bass tend to have almost unbroken rows of dark spots, one for each scale, on their sides.  They are a little less likely to be marked with the large, irregular blotches that often make these fish look like they are dressed in camouflage, but those dark markings can show up very strongly at times, depending upon the fish's mood and stress levels.  There are a few other distinguishing characteristics that one can find if so inclined, including scale counts--northern rock bass have 36 to 47 scales along the lateral line, and 21 to 25 scale rows across the breast from pectoral fin to pectoral fin.  Northern rock bass grow the largest of the three species, attaining lengths of over 12 inches; the Missouri record still stands at 17 inches and 2 pounds 12 ounces. The specimen in this illustration was taken on Huzzah Creek, a Meramec River tributary. 

Shadow Bass (Ambloplites ariommus)

This is the native species of the Arkansas, Black, St. Francis, and Castor river systems.  It also occurs in clear drainage ditches in the Bootheel of Missouri, and the rock bass of far southwestern Missouri may show shadow bass characteristics.  The main distinguishing mark is the heavy mottling of the anal fin.  The rows of dark spots on the sides are usually interrupted; some scales will be lacking their spot, and in certain color phases the black spots may be almost indistinguishable from the background color, especially very darkly "camouflaged" fish.  Shadow bass tend to stay more darkly and heavily marked with large, irregular blotches than the other species. Shadow bass usually have 41 or fewer scales along the lateral line. They have larger scales on their breasts--15-18 scale rows from pectoral to pectoral. Shadow bass are the smallest of these species, seldom growing larger than 9 inches. This specimen was taken on the St. Francis River.

Ozark Bass (Ambloplites constellatus)

This species is native only to the upper White River system, including all streams flowing into the White River above the mouth of Black River.  The anal fin is largely unmarked and does not have a black margin, which distinguishes it from the other two species.  The spots on the sides do not form obvious rows but are almost randomly scattered and sometimes irregularly shaped, giving the fish a freckled appearance, and are always prominent, never obscured by the camouflage pattern.  Ozark bass are also noticeably more slender than the other species.  They have 40 to 48 scales along the lateral line (usually more than 41 scales), and have 20 or more scale rows across the breast.  Ozark bass can attain lengths of better than 10 inches; the Arkansas state record "rock bass" was an Ozark bass, and weighed 1 pound 8 ounces. This specimen was taken on the North Fork of the White River.