Carinotetraodon imitator
One of the smallest pufferfish, native to India's Western Ghats.
Carinotetraodon imitator, called the dwarf Malabar pufferfish, is a freshwater species from India’s Western Ghats. It ranks among the world’s tiniest pufferfish and looks very similar to its relative, Carinotetraodon travancoricus.
Males reach a maximum standard length of 2.65 cm (1.04 in). The species shows clear differences between sexes. Males have dirty yellow to orange bodies and fins covered in dark blotches. Their underside is dirty white to dirty yellow, turning brownish near the midventral line, forming a stripe from the lower lip to the caudal peduncle; this stripe is wider and darker around the anal fin. Males also have an erectable skin keel along the belly and back. Females share the dark spots and blotches but have light brown to beige bodies with a white belly. They lack the midventral stripe, though the area near the anal fin is darker and may extend as a short stripe to the lower half of the caudal fin base. Pattern and color vary among individuals of both sexes, and the dark spots can be bold, faint, or broken into smaller spots.
To tell C. imitator from C. travancoricus: males have brighter yellow coloration and smaller, fainter blotches, and they lack the iridescent blue lines behind the eye. Females have smaller, fainter body blotches than C. travancoricus females, plus many small spots (though C. travancoricus females may also have small spots between larger, darker blotches). The biggest difference is body spination, which is greatly reduced in C. imitator.
The species was first described in 1999 from aquarium specimens in Germany. Importers learned from exporters that the fish came from India, likely small rivers in Kochi (probably Ernakulam and neighboring districts). Those specimens were kept with C. travancoricus, so the two species may occur together or were mixed by collectors or exporters. Since then, C. imitator has been found in the mid- and lowland reaches of the Kumaradhara and Addahole rivers (Netravati River basin in Karnataka) and in shallow streams. It lives in waters with sand, gravel, or stone substrates. Its full distribution remains unknown.
Reproduction has only been observed in captivity. Water was kept slightly brackish (10 L of seawater per 60 L of freshwater) at 20–24 °C (68–75 °F). During courtship, males erect their keels and turn bright yellow to orange with no markings.
Quick Facts
- Taxon
- Carinotetraodon imitator
Facts from the source article.
Lore & Background
The species was first described in 1999 based on specimens in an aquarium in Germany. Information gathered through the importer from the exporter indicated that the species originated in India, found in small rivers in Kochi, probably from Ernakulam and neighbouring districts. The specimens were being kept with a number of Carinotetraodon travancoricus, suggesting either the two species occur together, or were later mixed by collectors or exporters. They have since been found in mid- and lowland reaches of Kumaradhara and Addahole, Netravati River basin in Karnataka, as well as shallow streams. They inhabit bodies of water with sand, gravel, or stones making up the substrate. There is no information on its complete distribution.
C. imitator is sexually dimorphic. Males have bodies and fins which are dirty yellow to orange in colour and are covered in dark blotches, with an erectable skin keel along the ventral and dorsal surfaces. Females are light brown to beige with a white ventrum and also possess dark spots and blotches. The patterns and colouration varies between individuals of both sexes. The species can be distinguished from its congener by brighter yellow colouration in males, smaller and fainter blotches, lack of iridescent blue lines behind the eye, and greatly reduced body spination.
Reader's Guide
The dwarf Malabar pufferfish is notable for being one of the smallest pufferfish in the world, with a maximum recorded standard length of only 2.65 cm. Its significance in the aquarium trade is considerable, as it is widely available internationally despite being listed as data deficient on the IUCN Red List. The species is one of the least known freshwater fish of the Western Ghats, and may be 'a very rare species.' Overharvesting for the aquarium trade is a potential threat. Reproduction has been observed only in captivity, where spawning occurred in java moss in slightly brackish water. Males court females by erecting their keels and becoming bright yellow to orange without marks, and defend the spawning territory. Eggs hatch after seven days, and larvae use adhesive cells along the ventral yolk sac to attach to substrate. The species' complete distribution, population, biology, and threats remain poorly understood, though local exporters may have more knowledge.
Did You Know?
- Males of this species can erect a skin keel along the ventral and dorsal surfaces during courtship.
- The species was first described in 1999 from specimens in an aquarium in Germany.
- Eggs hatch after seven days at 22–24 °C, and larvae are 3.5 mm long with adhesive cells on the yolk sac.
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