Meeting Notes

November, 2011

Bob Bock, Native Killifish
63 present, 196 items in the auction

Why are they called Killifish? Dutch settlers came to North America and the waterways were called “kills” and these were the fish that inhabited them.

Two main groups of Killifish: Cyprinodontidae and Fundulines:

Topminnows and killies, long bodied fish that live at or near the surface of the waters in North America.

Local Killifish are found throughout the Chesapeake Bay drainage, widespread starting north of here and finishing way south. Some down through Venezuela. Many look alike. One freshwater killifish: diaphanous.

Most are salt marsh dwellers. The Northeast habitat is salt marsh. Pools that form contain L. parva. F. luciae at shoreline. Low tide F. Hetreroclitus, c. variegatus.. Open water has f. majalis.

Rainwater killifish Lucania parva: Docile, shows best in tank with lots of plant growth.

Spotfin killifish, Lucania parva, found in marshes, lives in pools above tideline. environments, extremely pollution tolerant, tolerates temperature extremes, low oxygen, high genetic variability, fast maturation.

Tolerances vary.

Mummichog have been found in the New Jersey Meadowlands where there are heavy metals; in Norfolk where there is creosote, and next to garbage dumps. Bob said they can live in the foulest conditions.

“What I could never figure out is how these things could survive all this pollution and the only thing that lives there are these mummichog. I did some research on it and found a teacher at Rutgers University who has studied them and found that the genetics were very, very different. The fish in Newark Bay had adapted to mercury and the heavy metals. They had chemical pathways that helped them survive, but they paid for it, and they were very slow and couldn’t catch the grass shrimp that they needed to eat. In this area the shrimp grow big because the mummichog have lost speed in exchange for this pathway. The species is not generically pollution tolerant—it is particularly well suited to specialization and adaptation—so if you take a species from an extreme micro-environment, it won’t necessarily be able to survive outside of that environment.”

Sheepshead Top Minnow, Cyprinodon variegatus: from the baitfish. They can be full of parasites, so treat for infestations. This is the archetype of the top minnows. Males turn blue with yellow fins. They might be adapted to freshwater. Teaspoon per gallon of Instant Ocean. They are a bit nasty and “cichlid-like”, keep them with mummichog. Have been kept with grass shrimp, but some of the grass shrimp got eaten. They are “like hyenas”. They want a claim on the bottom of the tank.

Breeding saltmarsh killifish: the males color up and they breed continually for months.

Fudulus majalis: found in a stream at Assateague Island. Higher salinity, open, deeper water habitat, large to 7 inches. Females have horizontal stripes and males have vertical stripes. Said to be peaceful. On Bob’s wish list. They color up when they breed.

Keeping local estuarine killifish: one teaspoon of Instant Ocean per gallon. In freshwater substitute calcium for salt. Dissolve a little limestone or driveway salt. Beware of some plants that can remove calcium. He uses java moss, but the red cherry shrimp didn’t make it. He feels that the java moss pulled all the calcium out of the water. Be careful, do your water changes.

Local Freshwater Killifish:

Striped Killifish: in the Potomac. He sees it on his snakehead hunts. Never got a snakehead, but he got a lot of these in Little Hunting Creek at Mount Vernon.

F. wrathmuni: he has never encountered.
F. catinatus: nice turquoise blue background with red stripes. “Nasty fish.”
F. lineatus: similar to golden wonder killifish but it gets a line.

Banded killifish: f. diaphanous in weed beds all over the bay system. Their range was originally in the great lakes and after the ice age they spread from west to east. They did a cross-wise migration and are now found on the east coast in freshwater areas of our drainage and not the saltwater drainage. You find them in Paint Branch Creek in College Park and also at Mount Vernon.

Northern Studfish: f. catenatus. Found in SW Virginia and border of Tennessee.. Males get a beautiful pattern, little bit on the nasty side, easy to breed.

Speckled killifish. F. rathbuini. South Central Virginia, North central North Carolina; in weedy areas.

Lined topminnow, F. lineolatus: male vertical stripes.

Starhead Topminnow Complex: Lineolatus is a member, they have little stars on their heads, little glowing dots on the head, probably some kind of species thing so they can ID each other. Lineolatus species is found down the east coast and around the Florida panhandle and along the northern coast.

Russet fin topminnow display, Casper Cox of NANFA…. He renamed his pool the “Cement Pond” and stocked it with killies.

Killies show best in natural settings with natural substrate and planted tanks.

Similar fish inland in Mississippi drainage: blackspotted top minnow, blackstripe top minnow, broadstripe minnow.

Florida: “Lots of neat stuff there to collect!” Get this: Florida Collecting Guide

Gulf Coast through Peninsular Florida: Banded topminnow, red-face topminnow, golden-ear topminnow.

Dwarf fundulines: pygmy killifish, (Georgia, Northern Florida) rainwater killifish (Maine to Texas). Bluefin killifish. (NC through Florida). They have nice dorsal fins either blue or red depending upon where they are from. “I keep killing them and I think it’s from the plants cleaning out the calcium. Maybe that’s why.”

Dwarf fundulines: keep in groups, lots of plants.

Marsh killifish, gulf killifish, longnose killifish: gulf coast Florida estuarine (Fundulus)

Rivuline Kryptolebius marmoratus in the mangrove roots in Florida. They thought it was endangered. It’s a hermaphrodite and can self-fertilize. True males are rare. Females unknown. Lives among submerged roots (in empty soda cans).

West Coast Fundulines: California killifish, Baja killifish. Bob has never kept them. and doesn’t know much about them. California is funny about letting people keep native fish.

Florida Cyprinodon (Pupfish): Diamond killifish, Goldspotted killifish, Sheepshead minnow.

Florida freshwater pupfish: Flagfish, Lake Eustis Pupfish. Aggressive temperament. They stake out a spot on the bottom and try to get a female. The pupfish are in the freshwater lakes in Florida that have established themselves there. One male per tank, generally aggressive to tank mates: tough surface dwellers. Sailfin mollies are good to keep with flagfish.

Western Pupfish: pupfishes survive extreme environmental conditions and tolerate temps from 32 to 115 degrees F, salinity as high as 132 ppt (ocean water is 35 ppt) and oxygen concentrations as low as 0.13 mg/liter the lowest known for any fish restricted to gill breathing.

Cyprinodon, 14 species listed in Peterson’s Field Guide. Robust body, deep in back, 1 row of tricuspid teeth in each jaw, long coiled intestine eats mostly plants, breeding male brightly colored. – from Peterson’s Field Guide.

In the Pleistocene, the Mojave Desert was much wetter. The large lakes dried up, leaving behind pools and springs. Pupfish trapped in these remnant water bodies became the species found today. The pupfish were able to survive out in the desert for ten thousand years!

Death Valley in Nevada/California border: Cyprinodon nevadensis mionectes found in little springs in Ash meadows in Death Valley. “Lots of silly people have come along and have taken large mouth bass, mosquito fish, sailfin mollies and crayfish and dumped them in these pools. The pupfish had virtually no competitors and the pupfish spawn seasonally and the largemouth bass just ate them. They organize groups to go out and dip net out and seine and collect the introduced species out of the springs.

Entrance to Devil’s Hole: Most extreme example of what pupfish have done. Death Valley National Refuge. Devil’s Hole Pupfish. Lightblue spawning male. Cyprinodon diabolis – no ventral fins. They live in a cave, people dive in there in the brown water. In the 1970’s they had legal fights and the pupfish were threatened. They are very tiny fish. Plants grow on a rock shelf and their numbers never go beyond 500 fish. They spawn on the weedy ledge. “They have this precarious existence living out there eating plants.” Sometimes owls will nest at the top of the cave. Owls will spit the owl pellets into the water. That stimulates the plants and the pupfish do better in those years.

Spawning killifish in temperate subtropical zones: Days get shorter, temperature drops, fish melatonin levels rise in winter and drop in the spring. To simulate winter conditions: reduce lighting to 8 hours a day or less, move tank to basement and unplug heater. Experts don’t know if it’s daylight or temperature that causes the melatonin to rise.

Most native killies are plant/bottom spawners. Add yarn mops to tank and check for eggs periodically.

Aquatic Ecosystems offers died coconut fiber embedded in rubber. Killifsh spawn in them. Would work well at home. Take mats out and put in another tank to raise fry. Hold eggs for a week at 68-74F. Hatch multiple batches at the same time. There are some fish that you have to take the eggs out and incubate them in peat moss. Commercial breeders use a plastic tub with foam stuffing. They get the eggs, put them on top of the foam, get the foam a little wet, then top with more foam at 72-76 degrees, with a saline spray, and hatch them all at once.

Collecting Rules/Regulations: Observe state and local laws, check with state fish and wildlife agency, fishing license required in most states, Virginia allows collection of small number of non game fish for private use, not legal to sell what you collect.

Submitted by Sherry Mitchell

Please note: all notes are taken while the presentation is ongoing. The author of the notes does her best to keep up and get pertinent information correct, but apologizes for any misspellings, errors or ommissions.