Carinotetraodon Travancoricus – Detailed Guide: Care, Diet, and Breeding

Carinotetraodon Travancoricus (Dwarf puffer fish) – Detailed Guide Care, Diet, and Breeding

Carinotetraodon travancoricus, commonly known as “Dwarf puffer fish”, is one of the smallest puffer fishes in the world. At the same time, their miniature size and “puppy” eyes should not deceive you because this fish species is predatory and, therefore, requires a special approach.

Carinotetraodon travancoricus is best kept in a tropical and species-only aquarium, as they can be quite aggressive and territorial.

If you are interested in keeping Dwarf puffer fish or want to learn more about them, this care guide will tell you everything you need to know, including their behavior, feeding preferences, ideal tank setups, and how to care for them.

Note: In India, Carinotetraodon travancoricus has been exploited extensively for the aquarium trade. As a result, it was enlisted as vulnerable by IUCN in 2010. Fortunately, this species is now successfully bred in captivity and available for sale.

Quick Notes about Carinotetraodon Travancoricus

Name Dwarf puffer fish
Other names Malabar Puffer Fish, Dwarf Pea Puffer, Pea Puffer Fish, Pygmy Pufferfish, and Dwarf Pufferfish
Scientific Name Carinotetraodon travancoricus
Water type Freshwater
Tank size (minimum) 5 gallons (~20 liters)
Keeping Medium
Breeding Medium-difficult
Size up to 0.8 – 1 inches (2 – 2.5 cm)
Optimal Temperature 75 – 80°F (24 – 27°C)
Optimal PH 7.0 – 8.0 
Optimal GH 7 – 14 
Dwellers Mid and bottom-dwelling
Nitrate Less than 60
Diet Omnivore
Temperament Peaceful
Life span up to 6 years
Color Form Yellowish and whitish with dark patches

Taxonomy of Carinotetraodon Travancoricus

  • Kingdom: Animalia (Animals)
  • Phylum: Chordata (Characterized by the presence of a notochord)
  • Class: Actinopterygii (Ray-finned fishes)
  • Order: Tetraodontiformes (An order of primarily marine and estuarine fish)
  • Family: Tetraodontidae (Includes pufferfishes, known for their ability to inflate)
  • Genus: Carinotetraodon (Refers to a specific genus of pufferfishes)
  • Species: Carinotetraodon travancoricus

In 1941, Indian ichthyologists S.L. Hora and K.K. Nair first described this fish as Tetraodon travancoricus.

In 1975, W. J. Dekkers reviewed the genus Tetraodon and considered Carinotetraodon a synonym of Tetraodon.

In 1999, Dr. Ralf Britz and Swiss ichthyologist Maurice Kottelat revealed that this fish has the modified parapophyses of Carinotetraodons. As a result, they transferred this fish from the genus Tetraodon into the genus Carinotetraodon.

The genus Carinotetraodon currently comprises 6 valid species of dwarf pufferfishes restricted to freshwaters in Asia.

Etymology of Carinotetraodon Travancoricus

The genus name “Carinotetraodon” is derived from the Latin word “Carino”, meaning “Keel or ridge” and the Greek word “Tetraodon” meaning “Four teeth”.

The species name “Travancoricus” is derived from the region of Travancore in Kerala, India, where the fish is usually found.

Distribution of Carinotetraodon Travancoricus

Carinotetraodon Travancoricus (Dwarf puffer fish) – Detailed Guide Care, Diet, and Breeding - destributionCarinotetraodon travancoricus is endemic to rivers of the Western Ghats in South India.

This species is mainly distributed in Chalakkudy, Pamba, Periyar, Kabani, Bharathapuzha, Vamanapuram, and Muvattupuzha rivers, lake Vembanad and kole wetlands of Thrissur, Kallar stream and Neyyar wildlife sanctuary of south Kerala.

The inferred extent of occurrence for this species is around 35,000 to 36,000 km2.

Habitat

Carinotetraodon travancoricus inhabits heavily vegetated slow-moving fresh waters.

Description of Carinotetraodon Travancoricus

Dwarf puffer fish is a relatively small freshwater fish. The adult size of this species ranges from 1 to 1.2 inches (2.5 to 3 cm) in length. However, the majority belong to sizes from 0.8 – 1 inch (2 – 2.5 cm).

 Distinguishing characteristics of Carinotetraodon travancoricus:

Body Shape: The body is ovoid in general, except the caudal area. It is covered with soft spines in both sexes. The fish’s tail base is short and thick.

Coloration: The general body color is yellowish dorsally and whitish below. The dorsal side is brownish to green dorsal side with irregular spots.

Color patterns: There are 2 black, oval patches on the sides before the dorsal fin. There’s also a dark, wide stripe from the top to the bottom fins on its sides. Two irregular dark patches and a V-shaped mark are located behind the eyes. Around its eyes, there’s a narrow, light stripe. This species also has irregular bands and triangular patches on the back. All the fin rays are yellowish.

Fins: The fins are rounded. The dorsal fin has 7–8 rays, the anal fin has 8 rays, and the pectoral fin has 16–17 rays. The ventral fin is absent.

Eyes: Eyes are very large “puppy” dog eyes. The lower margin of the eye is slightly below the mouth corner.

Head and Mouth: The head is large and blunt; jaw is modified to form a beak of four heavy, powerful teeth, two above and two below.

Lifespan of Carinotetraodon Travancoricus

According to the study, the lifespan of these fish in the wild is estimated at about as 4 years.

In aquariums, with appropriate conditions, Dwarf puffer fish can live for 6 – 8 years and there are reports of individuals living even longer.

Typical Behavior of Carinotetraodon Travancoricus

Sociality:

Carinotetraodon Travancoricus (Dwarf puffer fish) – Detailed Guide Care, Diet, and Breeding - groupIn the wild, Dwarf puffer fish are not known to be very social or swim together in large groups. However, it has been observed that in many cases, a pair of pufferfish tends to stay about 1 to 2 inches (2.5 to 5 cm) apart from each other.

Temper:

These little guys are pretty territorial and aggressive, especially towards their own kind and during mating. Males are way more aggressive and should not be kept in small tanks since they will definitely fight.

Note: It is important to monitor their behavior and be prepared to separate individuals if aggression becomes excessive.

Do not look at their tiny size, Dwarf puffer fish may show aggression towards other fish as well, even bigger ones! They are known to nip at other fish especially slow-moving or long-finned species. Thus, it’s essential to choose tankmates carefully.

It is highly recommended to keep them in a heavily planted tank to establish territories and minimize aggression.

Breaking the line of sight is an effective strategy to reduce aggression among Dwarf Pufferfish. This can be achieved by adding decorations, plants, or other tank features that create visual barriers and separate their territories.

Activity:

Dwarf puffer fish is active and curious. They tend to explore their surroundings and are often seen swimming around the tank.

They have a somewhat jerky, hovering motion like mini helicopters. Their ability to move in a hovering manner allows them to position themselves precisely and navigate through plants and decorations with ease.

Dwarf Pufferfish are not particularly fast swimmers compared to some other fish species.

Like other pufferfish, this species is capable of inflating its abdomen when threatened, visually appearing larger. This happens, for example, when a larger predator tries to eat it, and both fish can end up dying.

Placement in Tank:

They prefer to hang out near the bottom and swim in the middle of the tank. They enjoy exploring their environment and are particularly fond of areas with dense vegetation or places to hide.

Features:

  • Social level: Yes, but can be kept alone
  • Activity: Medium
  • Placement: Middle and bottom dwellers
  • Peaceful: Semi-aggressive
  • Territorial:Yes
  • Nippers: Yes

Diet of Carinotetraodon Travancoricus

During my research, I found some studies that go against the common idea that this fish is exclusively carnivore.

In one of the studies, it was suggested Carinotetraodon travancoricus to be an omnivore. The gut content analysis showed that

  • Insects (18.52%), such as dragonflies, damselflies, mayflies, aquatic bugs, etc.
  • Crustaceans (18.07%) such as copepods, moina sp., daphnia sp., ostracods, etc.
  • Annelids (14.30%)
  • Diatoms (14.02%)
  • Green algae (12.55%) such as Naviculasp., Cymbella sp., Syndera sp., Cocconeissp., Pinnulariasp., Fragillaria sp.,Nitzschiasp.,Spirogyra sp., Ulothrix sp., Shizogonium sp.,Pleurodiscussp., Uronema sp. And Oedogonium sp.
  • Sand (10.78%) and
  • Detritus (11.77%).

In another study, scientists found that algae constituted a significant portion (more than 60%) in both male and female diets, along with red worms and semi-digested animal matter, mainly comprising crustaceans and insect parts.

In the aquarium, Dwarf puffer fish can be fed a wide variety of live food such as:

Some Feeding Tips:

Properly feeding the Dwarf puffer fish is the most challenging aspect of caring for them. Dwarf puffer fish are pretty picky eaters.

  • When keeping them, you may find that they refuse such frozen food as shrimp, clams, etc.
  • Additionally, they rarely eat flakes, pellets, or other dry food. In this case, try combining it with live food.
  • They are not very fast swimmers, and this also applies to feeding. In a community aquarium, they will often be outcompeted for food by other fish.
  • Nothing triggers their appetite more than live and moving prey.
  • While they are predominantly carnivorous, it’s worth noting that in a well-balanced aquarium, they may also pick at algae and detritus from time to time. Nonetheless, their diet should still primarily consist of meaty foods to ensure they receive the necessary nutrients for their health and well-being.
  • It has also been observed that feeding Dwarf puffer fish twice a day (morning and evening) significantly reduces cases of them nipping at the tails of their tankmates.

Features:

  • Diet Type: Omnivore
  • Food Preference: Meat
  • Feeding Frequency: Daily

Are Carinotetraodon Travancoricus Plants Safe?

Yes, Dwarf puffer fish is completely safe to keep in planted tanks. They will not eat any healthy plants in the tank. This species does not eat living plant material.

Keeping and Caring for Carinotetraodon Travancoricus

These fish don’t tolerate ammonianitrites, or nitrates well. It is absolutely crucial to ensure the cycling process is complete before adding them to the aquarium. Ideally, it will be better to wait for at least a couple of weeks until the balance is completely established.

Tank size:

The minimum tank size for a single Dwarf puffer fish is generally considered to be a 5-gallon (20-liter) tank.

For a small group (3-4 fish), a tank size of at least 10 gallons (40 liters) is a good starting point.  A larger tank is always recommended to accommodate their territorial nature and reduce aggression.

Note: Dwarf puffer fish are not known for being prolific jumpers. However, it still may happen, especially if they feel stressed, scared, or if the tank conditions are not suitable. To minimize the risk: use a tight-fitting lid, lower the water level, use floating plants, etc.

Water parameters:

Temperature:  Dwarf puffer fish need water temperatures ranging between 75 to 80°F (24 to 27°C). They do not tolerate cooler temperatures well.

pH: The ideal pH range is between 7.0 – 8.0. In their natural environment, they thrive in alkaline waters. It has been observed that reducing the pH to 6.5 had negative effects on the fish.

Hardness: The recommended hardness range is 7 to 14 GH. They do not like soft water.

Monitor the water parameters regularly and do water changes every week.  

Lighting:

Dim lighting will be optimal for Carinotetraodon travancoricus. Bright light makes them stressed.

Related articles:

Water flow:

Still or very slow water currents are recommended for tanks housing this species.

Substrate:

Their natural environment is composed of mud and sand.

Related article:

Filtration:

No special requirements.

As long as you have got the filter that works great with the size of the tank you have got you will be fine.

Decorations and Plants:

Dwarf puffer fish requires plenty of hiding places, such as driftwood, plants, leaves, pipes, etc. Having decorations allows them to establish territories and can create visual barriers, helping to reduce conflicts.

Additionally, when they feel stressed or threatened, having places to retreat can help reduce their stress levels.

Interesting fact: The survival of this fish also depends on the chosen plants. The study examined the compatibility and survival of Carinotetraodon travancoricus with Cabomba and Ceratophyllum plants.

Cabomba plants worked better than Ceratophyllum. Planting Cabomba 2 – 3 inches (5 – 7.5 cm) apart led to higher survival rates. In their natural habitat, Dwarf puffer fish dominate in areas with gathered Cabomba plants, providing essential habitats and food in their natural habitat.

Important: I would like to stress again that placing these fish in open aquariums will be a huge mistake! The aquarium’s open layout proves unsettling for these fish.

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Breeding Carinotetraodon Travancoricus

While breeding Dwarf puffer fish can be a bit challenging, it is still possible to do even in home aquariums.

Maturity:

Females reach maturity slightly earlier than males. Dwarf puffer fish reach their first sexual maturity at 0.72 inches (18.33 mm) in males and 0.71 inches (18.0 mm) in females.

Sexing:

This species has clear sexual dimorphism. They also possess differential color patterns. However, these differential morphological features are not recognized easily in juvenile stages.

  • Females may have a more rounded body than males, especially when carrying eggs.
  • The coloration of males, especially during the breeding season, is much more vivid.

Males have a dark bluish band extending from the mouth to the caudal fin on the ventral side. The clear dark line runs medially on the ventral surface. Males also have a distinct pattern of closely arranged wrinkles just behind their eyes. The abdominal region of male fishes has a yellow color, a golden orange color seen on the base of the caudal, anal, and the dorsal fin in addition to a dark line on the caudal fin.
Females have Light black spots throughout their body, which mark the shining golden yellow spots.

Spawning:

Males try to attract females to the spawning site by swimming back and forth between the spawning site and females. At the same time, they often direct females by actively pushing them with their body and nibbling the belly.

If a female is ready to spawn she follows the leading male. They also do not eat much during the spawning period.

Fecundity:

Regarding fecundity, this species typically produces up to 10 eggs at a time. There can be up to 10 or more spawning bouts per spawning sequence. According to the research, the absolute fecundity ranges from 139 to 480.

Eggs:

These fish are not livebearers, they are egg scatterers.

The female releases eggs and the male fertilizes them in the water. The eggs then fall and adhere to surfaces like plants or substrates.

Eggs are large, about 1.43 mm in diameter. They are spherical, demersal, and adhesive, with a mass of small oil globules.

Parental care:

There is no fanning or other form of parental care except the defense of the spawning territory by the males.

Incubation:

Depending on the temperature, eggs hatch after 7 days at 71-75°F (22-24°C) and 5 days at 79-84°F (26-28°C).

Fry:

Hatched fry are about 3.5 mm long and do not have complete eye development. They have brownish bodies and two translucent vertical bands, one behind a large yolk sac and one at the end of the caudal fin.  

They can attach to surfaces using the underside of their yolk sac. The yolk is typically consumed by the fry after 4 days, and they start free-swimming after 6 days.

  • At 20 days after hatching, the fry measures around 0.25 inches (6.26 mm) in length.
  • At 62 days, the fish reaches approximately 0.4 inches (10.18 mm).
  • By 112 days, they’ve grown to about 0.58 inches (14.75 mm).
  • At 180 days, the mean size is around 0.6 inches (16.6 mm).

Feeding Fry:

As the yolk is depleted, the fry will require food, and this food will be Artemia sp. for the first 2 weeks.

Separate Breeding Tank:

Conspecifics, other fish species or even snails can eat the just-laid eggs. So, to increase the chances of eggs and fry survival, it is recommended to set up a separate breeding tank.

This tank should have fine-leaved plants or spawning mops where the eggs can be scattered and protected from adult pufferfish.

Maintain stable and suitable water conditions, including temperature, pH, and hardness, to mimic their natural habitat.

Carinotetraodon Travancoricus and Suitable Tankmates

These little ones may seem cute at first glance, but keeping Dwarf puffer fish with others can pose a significant challenge due to their semi-aggressive nature.

While you may come across stories online about them peacefully coexisting with other fish, in most cases, it’s only a matter of time. Therefore, the best choice would be a species-only aquarium.

Fish:

If you still decide to keep this species in community tanks (I repeat – NOT recommended), its tank mates should be all small fish species that are not big enough to eat or harass them.

Dwarf shrimp:

Do not keep Dwarf puffer fish with dwarf shrimp.

Personally, I would never recommend keeping this species with shrimp, especially if you have high-priced shrimp or plan to breed them.

These fish are predators. Therefore, they will definitely eat shrimplets. Furthermore, even adult shrimp, after molting, might end up on their menu. They can go after prey much larger than themselves including Amano shrimp and Ghost shrimp.

Of course, heavily planted tanks will provide some protection for the shrimp. However, in the long run, it will be a bad idea anyway.

Snails:

Dwarf puffer fish are not compatible with any freshwater snail.

They kill snails, mostly the smaller ones, but they only eat what protrudes from the shell. The rest of the meat remains and can lead to an increase in nitrogen levels as it decays.

Avoid:

 Related article:

In Conclusion

Dwarf puffer fish are one of the most unusual fish that can be kept in aquariums. They have a truly fascinating appearance, making them a mesmerizing sight.

If you decide to keep them, you need to understand that they are a little more high maintenance than other fish, and keeping them in a community tank is not easy.

References:

  1. Anupama, K. M., H. S. Hari Sankar, M. Rithin Raj, and M. Harikrishnan. “Reproductive biology of malabar pufferfish Carinotetraodontravancoricus (Tetraodontidae).” Journal of Ichthyology59 (2019): 545-554.
  2. Dahanukar, N., Carinotetraodontravancoricus, in The IUCN Red List of Threatened Species, Cambridge, 2011, no. e.T166591A6242813. 
  3. Britz, Ralf, and Maurice Kottelat. “Carinotetraodon imitator, a new freshwater pufferfish from India (Teleostei: Tetraodontiformes).” Journal of South Asian Natural History4 (1999): 39-47.
  4. Renjithkumar, ChelapurathRadhakrishnan, KuttanelloorRoshni, and KuttyRanjeet. “Feeding ecology of the endemic freshwater puffer fish Carinotetradontravancoricus (Hora & Nair, 1941) in Western Ghats hotspot, India.” International Journal of Aquatic Biology8, no. 5 (2020): 300-310.
  5. Anupama, K. M., and M. Harikrishnan. “Improved survival of Malabar puffer fish, Carinotetraodontravancoricus (Hora and Nair, 1941) in planted aquaria.” InternationalJournalofEnvironmentalSciences6, no. 1 (2015): 138-144.
  6. Anupama, K. M. “Studies on the life history traits of Malabar puffer fish Carinotetraodontravancoricus Hora and Nair 1941 inhabiting Pampa and Chalakkudy rivers South India.”
  7. Maceda-Veiga, Alberto, and Jo Cable. “Diseased fish in the freshwater trade: from retailers to private aquarists.” Diseases of Aquatic Organisms132, no. 2 (2019): 157-162.
  8. Ishibashi, Toshiaki. “Hiroyuki Doi, Harumi Sakai, Yusuke Yamanoue, Takayuki Sonoyama&.” Fish Sci81 (2015): 291-299.
  9. Dekkers, W. J., 1975- Bijdragen tot de Dierkunde 45(1): 87-142Review of the Asiatic freshwater puffers of the genus Tetraodon Linnaeus, 1758 (Pisces, Tetraodontiformes, Tetraodontidae).

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