Parapercis schauinslandi – Redspotted Sandperch

Parapercis schauinslandi – Redspotted Sandperch

Parapercis schauinslandii was first described by Steindachner in 1900. This fish belongs to the family Pinguipedidae, which is known as the sandperches. The family Pinguipedidae consists of seven genera with a total of 65 species. The genus Parapercis contains 26 species.

The genus name “Parapercis” is derived from the Greek “para” (beside) and “perke” (perch), which refers to the perch-like appearance of these fish. The species name “schauinslandii” honors the German zoologist Hugo Schauinsland, who collected the species in New Zealand in 1896-1897. Their common name is Redspotted Sandperch.

Synonym: Percis schauinslandii.

Description

General description:
Parapercis schauinslandii has an elongated body with a pointed snout. The color of the head and flanks varies from black or reddish to dark brown with alternating reddish stripes on the lower flanks. The dorsal fin has black base colors that become deep red towards the tip, while the second dorsal fin has a row of dark spots. The pectoral fins have two thin bright red stripes at the base, and the caudal fin has two dark spots at the base. This fish can reach a maximum length of 18 centimeters.

Differences between males and females:
There are no specific physical differences between males and females described in the available sources. Behavioral differences are also not documented.

Behavior and Temperament:
Parapercis schauinslandii is generally aggressive towards other fish and is best kept solitary in an aquarium. They are usually bottom-dwelling and often swim up to catch prey. They can be seen in small groups of 10-50 fish, but are often solitary or in small species-specific schools.

Hermaphroditism in Parapercis schauinslandii

Parapercis schauinslandii has a remarkable ability to change sex. This phenomenon, hermaphroditism, is an adaptive strategy found in several fish species, including Sandperches.

Sex change:
Parapercis schauinslandii is capable of changing sex, specifically from female to male. This process is called protogynous hermaphroditism, where individuals start life as females and later change into males. This usually occurs when there is a shortage of males in the population, causing a female to take on the role of a male to ensure reproduction.

Biological Mechanisms:
Sex change is regulated by complex hormonal processes that are influenced by social and environmental cues. When a dominant male disappears or dies, one of the largest and strongest females in the group may begin the transformation into a male. This process involves both physiological and behavioral changes, such as the development of male secondary sexual characteristics and the adoption of male reproductive behaviors.

Benefits of Hermaphroditism:
The ability to change gender offers several advantages:

• Reproductive Flexibility: It allows the population to respond dynamically to changes in the sex ratio, increasing reproductive success.
• Optimization of Reproductive Chances: In situations where males are scarce, females can take on the male role, increasing the chances of successful reproduction.
• Social Structure: It helps in maintaining a stable social structure within the group, which is important for the survival and well-being of the individuals.

The ability of Parapercis schauinslandii to change sex is a fascinating example of biological adaptation. This ability allows the species to respond flexibly to changes in population dynamics and to maximize reproductive success, which contributes to the survival of the species in their natural habitat.

Biotope

Parapercis schauinslandii is found in the Indian and Pacific Oceans, from the coast of East Africa to Pitcairn Island, and as far north as Japan and south to the Great Barrier Reef. They inhabit open areas with sandy and rubble substrates on deeper seaward and coastal slopes and on deep sandy reef flats, at depths between 9 and 170 metres.

Their natural habitat consists of sandy and rubble bottoms without much coral or rock.

Diet

In the wild:
Parapercis schauinslandii feeds mainly on zooplankton.

In the aquarium:
In an aquarium, they can be fed with fish and larger crustaceans such as shrimp and crabs. It is important not to keep small fish or invertebrates such as shrimp and crabs in the same aquarium, as they may attack and eat them.

Reefsafe:
Parapercis schauinslandii is not completely reefsafe, as they may eat small crustaceans such as shrimp.

The Aquarium

Aquarium size:
It is recommended to use an aquarium of at least 1000 liters for a single Parapercis schauinslandii. For multiple pairs, a larger aquarium is needed.

Setup:
The aquarium should be set up with sand as substrate and some rocks or hiding places. Coral is not necessary but can be added for aesthetic purposes.

Water parameters:
The best water parameters for Parapercis schauinslandii are a temperature between 22.5 and 29 °C, with an average of 27 °C.

Introduction to the aquarium:
It is best to introduce this species into a well-matured aquarium so that there are sufficient algae and microorganisms present.

Compatibility:
Parapercis schauinslandii can be kept with other larger fish that are not considered prey, such as larger angelfish, surgeonfish and triggerfish. They should not be kept with small fish or invertebrates such as shrimp and crabs.

Breeding in the Aquarium

There are no specific data available on breeding Parapercis schauinslandii in an aquarium. It is unknown which conditions are best for breeding this species.

Conclusion

Parapercis schauinslandii is an interesting and useful fish for larger aquariums, especially because of their ability to control bristle worms and small mantis shrimp. However, they are not suitable for beginners due to their aggressive nature and specific care requirements. It is important to keep them solitary or in very large aquariums with other large fish that are not considered prey.

Video

Author

John de Lange

Copyright image

Hristo Hristov