Fish


Here detained for our casual survey, blacknose dace (Rhinichthys atratulus) are common denizens of Little Crum Creek.

Just an inch long, these minnows could triple in size when returned to their shallow flows.

101_3283edcropA101_3295edcropA101_3286edcropCBut heavy rains often raise the creek to several feet of rushing water.

And I wonder how the tiny swimmers manage to weather periodic torrents sweeping through their usual riffles.

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Two weeks ago, from a considerable distance, I could see several fish splash and writhe in the clear-flowing stream’s gravelly shallows.

A little later, these 6-8″ fish were swimming together in a deeper pool just above the pebbly flow, often sheltering in the shadow of a large rock or far bank in a chasing game of touch and go, sometimes swimming side by side as if attached.

The black band lining each of these fish brings to mind the blacknose dace.  But that’s a tiny minnow, up to 5″ smaller than these.

Two fisherman friends agree that these look like suckers. And the PA Fish and Boating Commission lists four types of sucker in our part of the state.  Of those, I have seen only the creek chubsucker occasionally pictured with such a stripe. [See Update at bottom of post.]

There are many smaller fish, as well, too several and quick to identify just yet.

Whatever they are, certainly all are catching the heron’s eye.

. . . . . . . . . .

*UPDATE*

Though my original guess here was a creek chubsucker, I have since come across other information that makes me think this fish is not a sucker at all, but a kind of minnow: the creek chub.

In a 2010 presentation at Ridley Creek State Park, Dr. Thomas Cordrey of DelVal Soil and Environmental Consultants listed several fish observed in a downstream channel of Little Crum Creek:

  • common shiner
  • blacknose dace
  • creek chub (Semotilus atromaculatus)
  • pumpkin seed
  • green sunfish
  • white sucker

No mention of the creek chubsucker (Erimyzon oblongus).

Likewise, a PA DEP report omits the creek chubsucker from its list of fish in Crum Creek, the stream to which Little Crum Creek is a tributary.

Finally, in March of 2012, I saw a similarly behaved fish with pointed white bumps on each side of its head.

Could these be the tubercles grown by creek chubs during breeding time?

LCC.b 017 (2)

Seen from footbridge, Little Crum Creek Park, Swarthmore PA.