Sewellia sp. 'SEW03'

Overview

Often imported alongside SEW02, Sewellia sp. ‘SEW03’ remains unidentified. Its pelvic and anal fins lack an obvious intervening gap. Successful care depends on mature food-bearing surfaces as well as strong circulation and oxygenation.

Distribution & habitat

A Hue-area origin in central Vietnam is suspected for traded fish, rather than firmly established. Typical habitats of the genus are clear, shallow upland streams over rock, sand, and gravel. Well-lit submerged surfaces support dense communities of attached organisms.

Aquarium setup

Arrange ample stone surfaces for grazing and use substantial filtration supported by pumps or aeration. Turnover of roughly 15–20 aquarium volumes hourly is a useful reference. Combine regular water changes with lighting that sustains algae, preserving biofilm across most surfaces.

Old wood, hardy attached plants, and exposed filter sponges add shelter or grazing opportunities. Avoid strongly staining fresh wood, which reduces light penetration. Wait for biological maturity before stocking and secure the cover against glass-climbing escapes.

Diet & feeding

The main natural food is attached algae together with its microbial community; taking insect larvae is considered probable. Maintain diatoms and soft green algae rather than relying on tough brush growth. Vegetable and spirulina gel mixtures are useful supplements. In heavily grazed aquariums, grow spare algae-covered stones separately and rotate them.

Emaciated arrivals require special attention. Recovery can be difficult, so keep appropriate food continuously available while preventing competition.

Behaviour & compatibility

A group of six or more follows the genus’s tendency to form aggregations and helps distribute social pressure. Disputes over feeding sites may involve raised bodies and belly-to-belly displays, with males usually more dominant.

Dissimilar fishes are generally tolerated, provided they suit the current and oxygen regime. Other sucker-bodied loaches and bottom grazers may face serious competition. Give such mixtures ample floor space, structure, and food-bearing surfaces, especially when some species are shy.

Sexual dimorphism

Mature males are slimmer with a square snout and pectorals extending almost directly sideways. Soft tubercles occur on the front pectoral rays and upper head. Females have a broader outline, with a smoother contour between snout and fins.

Breeding

A trial based on related species can use coarse rounded gravel that is already biologically mature, algae-bearing rocks, and an air-powered sponge filter. Gravel spaces separate eggs from adults and shelter feeding fry. Cooler replacement water may stimulate activity, but these techniques are not an independent success record for SEW03.

Courtship in the genus includes pursuit, circling, and contact before the pair rises into the flow to spawn. Young lack the adults’ strong attachment ability. Begin with microscopic live foods and progress to Artemia nauplii and microworms as they forage above the gravel. Inspect canister filters for young before cleaning.