The Common Sucker
E who loves to peer down into the depths of still waters, often sees upon the sandy, muddy or rocky bottom several long, wedge-shaped sticks lying at various angles one to another. But if he thrust down a real stick, behold, these inert, water-logged sticks move off deftly! And then he knows that they are suckers. He may drop a hook baited with a worm in front of the nose of one, and if he waits long enough before he pulls up he may catch this fish, not by its gills but by the pit of its stomach; for it not only swallows the hook completely but tries to digest it along with the worm. Its food is made up of soft-bodied insects and other small water creatures; it is also a mud eater and manages to make a digestive selection from the organic material of silt. For this latter reason, it is not a desirable food fish although its flesh varies in flavor with the locality where it is found. The suckers taken along the rocky shores of Cayuga Lake are fairly palatable, while those taken in the mud of the Cayuga Inlet are very inferior in flavor and often uneatable.
Seen from above, the sucker is wedge-shaped, being widest at the eyes; seen from the side it has a flat lower surface and an ungracefully rounded contour above which tapers only slightly toward the tail. The profile of the face gives the impression of a Roman nose. The young specimens have an irregular scale-mosaic pattern of olive-green blotches on a paler ground color, while the old ones are quite brown above and on the sides. The suckers differ from most other fishes in having the markings of the back extend down the sides almost to the belly. This is a help in concealing the fish, since its sides show from above quite as distinctly as its back because of its peculiar form. The scales are rather large and are noticeably larger behind than in the region of the head. Like other fish it is white below.
The dorsal fin is placed about midway the length of the fish as measured from nose to tail. It is not large and appears to have twelve rays; but there is a short spine in front and a delicate soft ray behind so that it really has fourteen. The tail is long and strong and deeply notched: the anal fin extends back to where the tail begins. The ventral fins are small and are directly opposite the hind half of the dorsal fin. The pectorals are not large but are strong and are placed low down. The sucker has not a lavish equipment of fins but its tail is strong and it can swim swiftly; it is also a tremendous jumper; it will jump from the aquarium more successfully than any other fish. When resting on the bottom, it is supported by its extended pectoral and ventral fins, which are strong although not large.
The eyes are fairly large but the iris is not shiny; they are placed so that the fish can easily see above it as well as at the sides; the eyes move so as to look up or down and are very well adapted to serve a fish that lives upon the bottom. The nostrils are divided, the partition projecting until it seems a tubercle on the face. The mouth opens below and looks like the puckered opening of a bag. The lips are thick but are very sensitive; it is by projecting these lips, in a way that reminds one of a very short elephant's trunk, that it is enabled to reach and find its food in the mud or gravel; so although the sucker's mouth is not a beautiful feature, it is doubly useful. The sucker has the habit of remaining motionless for long periods of time. It breathes very slowly and appears sluggish; it never seizes its food with any spirit but simply slowly engulfs it; and for this reason it is considered poor game. It is only in the spring when they may be speared through the ice that there is any fun in catching suckers; it is at this season of the year that they move to shallow water to spawn; those in the lakes move to the rivers, those in the rivers to the creeks, those in the creeks to the brooks. Even so lowly a creature as the sucker seems to respond to influences of the springtime, for at that period the male has a faint rosy stripe along his sides. In the winter these fish burrow in the mud of the river or pond bottoms; they may be frozen and thawed without harming them.
There are many species of suckers and they vary in size from six inches to three feet in length. They inhabit all sorts of waters, but they do not like a strong current and are, therefore, found in still pools. The common sucker (Catostomus commersoni), which is the subject of this lesson, sometimes attains the length of twenty-two inches and the weight of five pounds. The ones under observation were about eight inches long, and proved to be the acrobats of the aquarium, since they were likely at any moment to jump out; several times I found one languishing on the floor.
The Common Sucker
Leading thought—The sucker is especially adapted by shape for lying on the bottom of ponds under still water where its food is abundant.
Method—If still water pools along river or lakesides are accessible, it is far more interesting to study a sucker in its native haunts, as an introduction to the study of its form and colors when it is in the aquarium.
1. Where do you find suckers? How do you catch them? Do they take the hook quickly? What is the natural food of the sucker?
2. What is the shape of this fish's body when seen from above? From the side? What is the color above? On the sides? Below? Does the sucker differ from most other fishes in the coloring along its sides? What is the reason for this? What do suckers look like on the bottom of the pond? Are they easily seen?
3. Describe or sketch a sucker, showing the position, size and shape of the fins and tail. Are its scales large or small? How does it use its fins when at rest? When moving? Is it a strong swimmer? Is it a high jumper?
4. Describe the eyes; how are they especially adapted in position and in movement to the needs of a fish that lives on the bottom of streams and ponds?
5. Note the nostrils; what is there peculiar about them?
6. Where is the mouth of the sucker situated? What is its form? How is it adapted to get the food which the sucker likes best?
7. Tell all you know about the habits of the suckers. When do you see them first in the spring? Where do they spend the winter? Where do they go to spawn? How large is the largest one you have ever seen? Why is their flesh usually considered poor in quality as food? Is there a difference in the flavor of its flesh depending upon the locality in which the fish lives? Why?