Argus Fish

Adults can reach a length of about 35 cm. The fish's body has a characteristic "quadrangular" shape, strongly compressed laterally, and a small, slightly protruding head. The dorsal fin is divided into two parts: the anterior part, located on top, is equipped with sharp, venomous spines, which are usually pressed against the body when the fish is calm. The second part of the dorsal fin, along with the anal fin, is located closer to the triangular caudal fin. This body shape allows the fish to easily move through narrow crevices in search of food. Young fish are greenish-brown with diagonal rows of dark stripes and many small spots. As they mature, their coloration changes to silvery, the stripes disappear, giving way only to rounded spots.

Its natural habitat is in the coastal areas of the Indo-Pacific region. The distribution range covers the coasts of India, extending to southern Japan, the Indonesian and Philippine archipelagos, and up to northern Australia. This fish can be found in marine, brackish, and even fresh water, where it inhabits flooded mangrove forests, estuaries (places where rivers flow into the sea), and the lower reaches of rivers.

This peaceful and calm fish prefers to stay in groups. It coexists well with other non-aggressive species capable of living in similar conditions. An adult scat treats anything that fits in its mouth as food, so tankmates should be of comparable size.

This species is considered quite hardy and can adapt to various water parameters if changes occur gradually. For a small group of Argus fish, an aquarium of 800–1000 L will be required. The tank's decor is chosen based on the aquarist's preferences. For example, if possible, a fragment of mangrove thickets can be recreated. However, one should not count on the longevity of live plants, as they will most likely be eaten. Successful keeping of Argus fish largely depends on maintaining high water quality. Although the main burden falls on the filtration system, regular maintenance procedures should not be forgotten. Weekly partial water changes and timely removal of organic waste are mandatory.

The diet of this species is based on plant components: detritus, filamentous algae, and phytoplankton. In addition, their diet includes zooplankton and small invertebrates. In aquarium conditions, dry flakes, granules, and other plant-based foods are acceptable.

In a home aquarium, spawning of the Spotted Scat is rare, and successful breeding is only possible for experienced aquarists. In nature, reproduction usually begins with the onset of monsoon rains in June-July. Abundant rainfall and the subsequent drop in water temperature serve as key stimuli for spawning.

Scats are susceptible to various diseases when husbandry conditions are violated, especially with low pH levels or a lack of water salinity. Among the specific problems is epidemic ulcerative syndrome, which causes skin lesions. The fish are also sensitive to parasitic infestations such as Trichodina and Argulus, the symptoms of which include swaying, itching, emaciation, and the appearance of visible parasites on the body. Incorrect water parameters often lead to stress, manifested as head twitching and hovering near the surface. To prevent diseases, it is necessary to maintain stable water parameters, avoid overpopulation, and ensure proper salinity, as prolonged keeping in freshwater significantly reduces immunity and shortens the lifespan of the fish.

When choosing scats, attention should be paid to the activity of the individuals and the cleanliness of their skin. Healthy fish should show curiosity, have bright coloration with a clear spot pattern, and actively respond to food. It is important to avoid specimens with signs of fin damage, ulcers, film on the body, or unnaturally lethargic behavior, as this may indicate bacterial infections or the consequences of prolonged stress from improper transportation and keeping conditions in the store. It is recommended to clarify what water the fish were kept in, as an abrupt change in salinity when transferring them to a home aquarium is a serious risk factor for their health.