Stiphodon maculidorsalis · Orange-fin Stiphodon

Overview

Formerly traded as Orange-fin Stiphodon or ST01, Stiphodon maculidorsalis is a western Sumatran stream goby. Both sexes carry black spotting over the head and upper trunk. Those marks are more useful than orange display coloration when checking identity, since a trade label may cover mixed species.

Distribution & habitat

Its documented range includes Bengkulu, West Sumatra, and Aceh in western Sumatra, Indonesia. The type locality lies south of Painan.

Typical habitats of the genus are short coastal streams with rock beds, loose stones, bankside vegetation, and fallen leaves rather than abundant aquatic plants. Clear, oxygenated water and sunlight support productive biofilm. Species and sexes may differ in the stone sizes they use, making a varied substrate and a choice of current positions useful in captivity.

Aquarium setup

Start with an aquarium at least 80 cm long. Keep the water clean and highly oxygenated, adding pumps or aeration where filtration alone is insufficient. Arrange rounded stones over sand or gravel with numerous crevices and visual barriers, especially for multiple males.

Sleeping or spawning gobies may excavate, so seat load-bearing stones directly on the base. Aged wood is usable; fresh wood that strongly stains the water works against the bright lighting needed for algae. Hardy Microsorum, Crinum, and Anubias can add shelter and grazing surfaces.

Introduce the fish only after the aquarium has matured. Change 30–50% of the water weekly while leaving algae on stones and other surfaces apart from the viewing pane. A secure cover is necessary because these gobies can climb glass.

Diet & feeding

Members of Stiphodon scrape benthic algae and attached microorganisms with specialized jaws and teeth, bracing themselves with the pelvic disc. Productive grazing surfaces must provide the main feeding opportunity; bloodworms or dry foods cannot serve as a permanent replacement.

Some fish accept sinking products and small live or frozen animal foods, but these are occasional additions. Softer green growth, diatoms, and cyanobacterial films are more useful than resistant black brush algae. Where growth is inadequate or other grazers consume it too quickly, cultivate stones in a separate brightly lit container and rotate them through the aquarium.

Check body condition before purchase. Recovery of thin fish can be difficult and requires suitable food immediately available without strong feeding competition.

Behaviour & compatibility

Experience with the genus supports carefully chosen communities of small, peaceful fishes with similar oxygen requirements. Bottom-dwelling companions must neither monopolize food nor defend the entire floor. Most cichlids, assertive loaches, and large fishes are unsuitable.

Males maintain loose territories, more noticeably when breeding. Multiple males need space, cover, and abundant food. Females tend to associate loosely; one male and at least two females is a practical starting group. Females may also group across species, so neither shoaling behavior nor a dealer's label proves identity.

Sexual dimorphism

Males range from gray-yellow to brown, with bright orange-yellow dorsal, caudal, and anal fins. The first dorsal becomes extended and pointed, and the fins carry contrasting dark and pale bands. Dark flank bars vary with mood.

Females have shorter fins, sometimes with orange on the first dorsal but weaker color elsewhere, and may show a lateral stripe with additional bars. Black marks on the head and upper trunk occur in both sexes; males also have pectoral spotting. Use several features together with locality rather than relying on overall darkness.

Breeding

The genus spawns in freshwater but depends on a marine larval stage before juveniles return upstream. In studied congeners, males guard large numbers of tiny eggs attached beneath stones. Eggs around 0.5 mm across can number close to 10,000 and hatch within a day.

New larvae lack fully functional feeding and sensory structures. Their yolk lasts roughly three to four days, during which they must reach the sea. Pelagic development, coastal settlement, and the climbing return journey are linked stages; seeing guarded eggs in freshwater does not demonstrate successful rearing.

A study of Stiphodon percnopterygionus recorded a pelagic period of 78–146 days, longer under cooler conditions. This illustrates the complexity of the cycle but is not a species-specific schedule or salinity recipe for S. maculidorsalis.

Notes

Shipments have included mixed species, only one sex, or fish mislabeled Stiphodon zebrinus. Reliable collection information and head spotting are better identification aids than the Orange-fin name.

Localized Sumatran stream fishes may be affected by habitat loss, pollution, and introduced fishes. Those concerns deserve attention without assuming that a broad commercial label identifies a particular threatened population.