Fundulus kansae

Fundulus kansae originates from drainages to the north of the Red River of Texas and the Texas-Oklahoma border (USA). They are found in small, loosely organized schools composed of fish of the same general size. The species inhabits shallow, turbid waters over sandy-bottom, with slow to moderate current and elevated dissolved solids. Normally found in shallow (rarely deeper than 15 cm), sandy-bottomed streams; many localities highly alkaline or saline. Fish observed in pools when water temperature was as high as 35°C.  During periods of inactivity, it often lies buried in the sand with only its head showing. This behavior may allow the fish protection from the effects of high temperature by allowing a decrease in metabolism; also, the sand is considerably cooler than the water. Schooling Fundulus kansae, when alarmed, will respond as a unit in flight or concealment; the latter achieved by burying in the substrate.

Spawning season occurs from June to August; spawning observed at water temperature of around 28°C. During the spawning period from early June to early August, there may be three or more separate periods of spawning activity during the spawning season. Each spawning period follows a moderate or heavy rain, which suggests that spawning activity is stimulated by a sudden freshening of the water or a change in water temperature. Males do not establish territories but become aggressive toward each other while spawning and compete vigorously for the attentions of the females; spawning occurs during a brief pairing of a single male and female. The eggs are deposited over sand or gravel and rubble in water less than 10 cm deep; eggs are left unguarded. Fish attains sexual maturity at one year of age, and at a length of approximately 35 mm TL. They became sexually mature in the 2nd summer of life.

Fundulus kansae are omnivorous. Generalist feeder with bulk of diet composed of insects and other aquatic invertebrates; fish consumed diatoms and other plant material when invertebrates are difficult to obtain; when diatoms are few in number, fish consume large amounts of sand as they fed on the available layer of diatoms that grew over the sandy bottom. While adapted for top-feeding, this species will feed on the bottom in shallow sandy streams, primarily ingesting insect larvae, especially those of Chironomidae and Ephemeroptera. Bottom-feeding is achieved when the head is tilted downwards and forced into the substratum past the eye.

A tank with a minimum surface area of 90 cm x 40 cm is recommended for a small breeding group and this should be literally stuffed with woollen spawning mops and/or fine-leaved plants like Java Moss to allow the fish respite from one another. Use of a sandy substrate is required. The tank requires good filtration and clean, fresh water. Lighting should be relatively strong to encourage the growth of algae which provides an additional food source for both adults and fry. Ideally situate the tank in such a way that it receives sunlight for as much of the day as possible. The setup with a breeding group of 8 – 10 fishes works well since no single specimen can be targeted excessively. A higher ratio of females to males is recommended but not essential provided the amount of cover is sufficient. The eggs incubation period varies with temperature but is normally 10 – 14 days with the young fish able to accept Artemia nauplii, microworm and similar foods as soon as they are seen free-swimming. If conditions are satisfactory they grow quickly. Small daily water changes of around 10% tank volume are also recommended to ensure optimal growth rate.

Fundulus kansae are active over a wide temperature range of ~02°C – 30°C and is even known to survive under ice for brief periods. In captivity it certainly fares best when offered a cooler period during winter months since if constantly maintained under warm conditions noticeable reductions in both lifespan and fecundity become apparent. It also seems to benefit from a diurnal rhythm of warmer days and cooler nights and can actually be kept outdoors year round in many parts of the world.

Species Summary:

Scientific Name: Fundulus kansae (S. Garman, 1895)
Family: Fundulidae
Distribution: Drainages to the north of the Red River of Texas and the Texas-Oklahoma border (USA)
Disposition: Slightly Timid, Semi-Schooling Fish
Total Length: 80 – 90 mm
Spawning Method: Egg Scatterer
Breeding Proportion: Group of Males and Females
Breeding Difficulty: Demanding
Incubation Period: 10 to 14 Days at 21°C – 22°C (water incubation)
Fry Size: Medium (can take Microworms and BBS right after hatching)
Sexual Maturity: 12 – 15 Months
Life Span: 2 – 3 Years (depends on food and keeping conditions)
Filtration: Moderate
Water Changes: 1/3 Weekly
Salt: 1 Teaspoon of Seasalt per 3 Liters of Water
General Hardness: 10 – 20 dGH
pH: 7.0 – 8.0
Temperatrure Range: 10°C – 28°C
Lighting: Strong Light (a few hours of natural sunlight each day is beneficial)
Diet: Live and Frozen Food
Keeping Difficulty: Less Demanding


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