Herrera’s Mud Turtle

1 Overview

Herrera’s mud turtle is one of the more ferocious mud turtles. Its looks resemble the tiger-striped razorback, but its temperament is like that of the narrow-bridged musk turtle — great fun to keep, though among mud turtles it is relatively expensive, so few people keep it.

Chinese Name: Herrera’s Mud Turtle

Binomial: Kinosternon herrerai

Habitat: intermittent waters below 800 m elevation and free-flowing streams; the waters it lives in are somewhat brackish.

Size: large individuals reach 17.5 cm, with a slightly semicircular shell.

Diet: omnivorous, eating wild figs, beetles, ants, myriapods and other invertebrates; in captivity usually fed meat or small fish. Active both day and night. Oviparous. Price is around 5000 RMB, varying with size.

Kingdom: Animalia

Phylum: Chordata

Class: Reptilia

Order: Testudines

Family: Kinosternidae

Genus: Kinosternon

Distribution: Mexico (intermittent and brackish lowland waters below 800 m).

2 Physical Characteristics

Viewed from above it looks much like an egg. It resembles the tiger-striped razorback but has a larger head and a rounder shell.

Large individuals reach 17.5 cm, with a slightly semicircular shell. The broad area behind the central carapace: the first vertebral scute is stretched front-to-back and very narrow, so it does not touch the second marginal. The 2nd-5th vertebral scutes are wider than long, or about equal.

Adults have a single central keel; juveniles may show a clearer lateral keel running front-to-back on each side. The 10th and 11th marginals sit higher than the preceding ones. The carapace is usually olive or brown with black seams between adjacent scutes. The plastron is narrow with a notch at the rear. In males the front hinge plate is longer than the rear one; in females the reverse.

The plastron and bridge are usually yellow or light brown with no obvious spots or stripes. The large head has a slightly protruding snout and a strong hooked upper jaw; the head is light grey with spots on the back and sides, the cream upper and lower jaws carry black stripes, and the chin has two clear barbels. The limbs are light grey with coffee-coloured spots; the tail ends in a horny spur. This turtle has 56 pairs of chromosomes. Males are larger than females and have a long, thick tail; females have the larger plastron.

3 General Care

Some keepers try mixing species, which is wrong here: Herrera’s mud turtle is very aggressive and unsuitable for mixing. Other points to watch:

Environment: all mud turtles need land (especially the spotted and helmet types) — always provide a basking spot to prevent shell shedding and rot. Musk types sometimes do without, especially the razorback. Although this turtle does not demand much light, some real sun is still necessary; do not expect imported equipment to replace the sun.

Temperature: keep the water-to-air temperature difference within about 3°C and your turtle will essentially avoid colds and even pneumonia.

Water changes: necessary, but too frequent or too large a change is also bad. With filtration, changing at most one third of the water per week is enough. Water changes can also trigger colds and shell shedding, so control temperature and volume, especially in winter.

Food: feeding every 2-3 days is enough; even hatchlings need not be fed daily, and overfeeding only burdens the gut.

Can it be mixed? It is a very aggressive species, so avoid co-housing. If you must, control density. Strongly advise against putting feeder fish in a mixed tank: if the turtles bite each other, the fish will attack the wounds, causing serious bacterial infection.

4 Captive Habitat

The setup need not be elaborate — you are not growing it as a moss-back turtle — just keep water quality and temperature right, plus basking and mixing considerations.

Water depth: hatchlings swim better than some native turtles but should be kept at ‘over-the-back’ depth; once above 5 cm you can gradually deepen, with water temperature best above 25°C. Do not rush depth or overfeed, and the hatchling will thrive. Put driftwood in the water for two reasons: it gives a climb/rest/sleep/bask spot and improves water quality — this turtle prefers slightly acidic water. Mud turtles are best given a floating island or an emergent basking dock; water should not be too deep, as their swimming is weaker than the musk types.

Mixing: possible, but Herrera’s mud turtle is naturally fierce — control density strictly. More space is better, and hides are essential (plants, caves, large rocks, driftwood). Fights can be brutal: you may find the tank already red by the time you notice — gouged eyes, bitten-off claws, half-severed necks happen. Do not underestimate its bite; though below alligator-snapper level it still threatens its own kind.

Basking: put the turtle in a container with a little water and set it in the sun. The container should be white and escape-proof; add a thin layer of water to prevent dehydration, just enough to cover the head when it lowers it. Keep it short — about an hour, two or three times a week.

5 Feeding

Can it eat pellets? Many think pellets, despite balanced nutrition, contain preservatives and should not be fed long term. Is that right? Read on.

Pellets: base the diet on good-quality pellets. Some worry about preservatives and colourants, but the two pellet brands I mean here bring more benefit than harm — nothing is perfect, so do not expect a food that is 100% good for the turtle. Long-term shrimp feeding easily causes carapace deformity and gut problems, especially in hatchlings and newly arrived turtles.

Fish: if you insist on fish, quarantine them first so they expel gut contents, or freeze them before feeding — low temperature kills bacteria and lowers risk. I始终保持 the view that hatchlings should not eat shrimp or fish; just let them eat pellets, which already contain all needed nutrition. A bonus: pellets help control water quality, because fish and shrimp are extremely high in protein and any meat left in the tank quickly stinks — and ‘stink’ is protein.

Feeding notes: only when the turtle is healthy should you offer a little shrimp. Long-term fish feeding is also unwise — small fish live in the environment and carry many bacteria and parasites; hatchlings eating fish can even die suddenly, perhaps from fish bones, since the turtle’s digestion is fragile. You may feed fish for a long time with no trouble, but if one batch in a hundred is bad, it is fatal to the turtle.