This week for Flora and Fauna Friday we have a minute mosquito munching minnow, the Eastern Mosquitofish (Gambusia holbrooki).
The Eastern Mosquitofish is native to the southeastern United States. Here in the Lowcountry, it can be found in practically ever permanent freshwater body of water, from the largest lake and the widest swamp to the shallowest woodland pool and narrowest wet ditch. They can be found everywhere and easily found. A quick scan of a pond edge will almost certainly uncover a half dozen Mosquitofish lazily swimming just below the surface. Mosquitofish are only an inch or two in length with the profile of an elongated teardrop from above. From the side they have a mostly rectangular shape with an upturned mouth and a slight pot-belly. Their coloration is a drab mix of translucent gray and greenish-brown, sometimes with a black bean-shaped spot at the back of the abdomen. They’re a very no non-sense fish. They provide a very clear ecosystem service, mosquito control. Mosquitofish primarily eat algae and plant detritus but, when afforded the opportunity, they’ll eat their fair share of aquatic invertebrates.
As you know, mosquitoes lay their eggs in stagnant pools of water. They do this so their larvae can avoid predators. Those eggs hatch into free swimming larvae that feed on plankton until metamorphosing into blood-sucking annoyances. Well, Mosquitofish just so happen to love living in stagnant water bodies. So a large reason as to why mosquito populations aren’t any worse than they are is because of today’s dear old Mosquitofish. Mosquitofish are specially adapted to life in shallow, hot waters with dangerously low oxygen and pH levels as well as other water chemistries that are deadly to many fish. Mosquitofish seek out these inhospitable wetlands for their own safety, as few other fish will follow them here. However, Mosquitofish are still very common on the fringes of large water bodies as their small size allows them to stick right up against the water’s edge and out of harms way.
