Come April, all life begins to stir. Not just on land, but in the water as well; and not just for big fish, but little fish too.
Mummichogs are small fish (only about 5 to 7 inches long as adults) with a fun name. By most accounts, the word “mummichog” is an Algonquian Native American name that comes from the Narragansett people who for many thousands of years once occupied all of present-day Rhode Island. Many of the early Narragansett people were keen observes of the natural world. They came up with the word mummichog, which means “going in crowds,” after observing the fish swimming in large schools close to a shoreline. The word describes the little fish so well that we still use it today, thousands of years later.
The mummies don’t look like much, small pale fish with a tinge of olive for females and olive-yellow with some dusky bars for males. Yet, they belong to an important group of schooling fishes known as killifish. The killifish are an important food source for larger fish, such as striped bass and bluefish, and coastal birds including herons, egrets, and terns. Since killifish and mummichogs are able to withstand poor water quality conditions including low oxygen levels and variations in salinity, animals are able to find an easy and quick meal throughout the estuary and feast on these small fish no matter the environmental conditions. A perfect fish for the often muddy, messy waters of New York Harbor.
This time of year, the mummies are starting to become more active in local marshes. They have just spent the winter in a relatively sluggish state in creeks and small waterways where they buried themselves six or eight inches deep into the mud and muck.
Now as winter ends, the marshes around New York Harbor are preparing themselves as nursery areas for many species including mummichogs. It begins with the sun warming the mud and spring rains discharging nutrients into the water. This creates vast plankton populations and helps feeds small fish such as mummichogs.
Mummies are omnivores. They have been known to feed on all sorts of edible things, but seem fond of diatoms, sea lettuce, and other vegetable matter; and small shrimps and juvenile fish. They can also quickly gather around any dead fish or other bit of carrion to gobble it up quickly.
This time of year, though, the mummies have more on their mind than just food. They are becoming sexual charged in local saltwater wetlands and thinking of creating the next generation.
Spawning probably takes place from May to early August, but males are becoming brilliantly tinted now and in the process of pursuing females, who are showing off silvery bellies. Males who are the most highly colored or most excited typically spawn with the most females.
According to Henry B. Bigelow and William C. Schroeder in the Fishes of the Gulf of Maine, mummichogs “spawn in a few inches of water, seeking shady spots. At the moment of spawning the male clasps the female with his anal and dorsal fins just back of her anal and dorsal, usually forcing her against some stone or against the bottom, the bodies of both are bent into an S and their tails vibrate rapidly while the eggs and the milt are extruded. Occasionally, pairs clasp and spawn free in the water without coming in contact with any object, and sometimes a female is seen to pursue and court a male.”
When tides are highest during new and full moon evenings starting next month, female mummichogs will swim far up into tidal marshes to deposit over 400 eggs per female in clumps on the leaves of marsh grasses or in empty mollusk shells. Females deposit eggs far away from hungry males who might eat their own young.
In about two weeks, during the next highest tide, the eggs hatch. The young mummies stay in small pools in the marsh to avoid predation including adult mummichogs. It will take about two years for the young fish to reach sexual maturity.
Many mummichogs only live for three years. Certainly life is short when you are low on an aquatic food chain, providing so much food for so many animals around New York Harbor.