Myers's Hillstream Loach

Adults can reach a length of 5–6 cm. The fish's body appears slightly flattened, and large pectoral fins serve as reliable support, allowing it to hold onto the surface of rocks and boulders, counteracting the force of the current. Their function is less about swimming. The dorsal fin is adorned with a spotted pattern and has a red edge. The fish's body itself has a yellowish-brown coloration. There is a closely related species, Pseudogastromyzon cheni, widely known as the Chinese Hillstream Loach, which inhabits the same geographical areas and has an almost identical appearance. These species can only be distinguished by precise measurements of certain morphological parameters. Specifically, it is necessary to measure the distance between the beginning of the pectoral fin and the beginning of the pelvic fin (these are points B and C). Then, the distance from the beginning of the pelvic fin to the anus (points B and A) must be determined. If these two measurements are equal, you have P. myersi. If the first measurement (1) exceeds the second (2), it can be confidently stated that it is P. cheni. For the average aquarist, these subtleties of species identification are not of great importance, as both species require exactly the same keeping conditions.

The species inhabits fast-flowing, well-aerated shallow streams and tributaries with rocky bottoms in Guangdong Province, China, and Hong Kong. In natural conditions, the fish prefer areas with clear water where a rich layer of periphyton and biofilm develops on the surface of rocks. The climate in the range is subtropical, monsoon, which causes seasonal fluctuations in water level and current velocity.

In their natural habitat, these fish compete with conspecifics and other species for limited food resources, although they also need the company of their own kind. In the confined space of an aquarium, they may exhibit aggression towards other individuals of their species. The possibility of cohabiting Myers's Hillstream Loaches depends on having a sufficiently spacious tank where each will have enough room. These creatures can be compatible with other species that thrive in similar conditions with moderate to strong currents and relatively cool water. Potential tank mates include members of the genera Barilius (e.g., Barilius dogarsinghii), Garra (such as Garra rufa, Garra mullya, Ceratogarra cambodgiensis), Devario (including Devario devario, Devario aequipinnatus, Devario malabaricus), Rhinogobius (such as Rhinogobius candidianus), Akysis (Akysis variegatus, Akysis hendricksoni, Akysis vespa), and Hara (Hara jerdoni, Hara hara).

For a group of 6–8 fish, the optimal aquarium volume is from 100 liters. The fundamental conditions for successful keeping are clean, oxygen-rich water and the presence of a moderate to strong current. A powerful filter will help create the necessary water movement and ensure a sufficient level of dissolved oxygen. It is recommended to choose a filter whose hourly output exceeds the aquarium volume by 10 times. For example, for a 100-liter aquarium, a filter capable of pumping about 1000 liters per hour would be required. In a home aquarium, slightly lower values are acceptable, as the suggested ratio might create too turbulent a flow. The decor should include pebbles, rocks, boulders, snags, and other secure elements that will not be moved by the water flow. Live plants are not an essential element, but if desired, aquatic mosses and ferns can be used, attaching them to the surfaces of rocks or snags. The lighting level should be high, as bright light promotes the growth of some algae, which can serve as an additional food source for the fish. In their natural environment, Pseudogastromyzon feed on diatoms and filamentous algae, as well as various microorganisms living in the algal film. Therefore, it is advisable to stimulate the growth of such algae in the aquarium. The main diet can consist of sinking plant-based foods (granules, tablets). Additionally, it is recommended to include protein supplements in the menu, such as bloodworms or Artemia.

In the wild, Pseudogastromyzon feed on diatoms and filamentous algae, as well as various organisms living in the algal film. Based on this, it is desirable to create conditions for the growth of such algae in the aquarium environment. The main diet can consist of sinking foods (e.g., granules or tablets) primarily plant-based. It is also recommended to add protein-rich foods, such as bloodworms and Artemia.

Breeding is possible in aquarium conditions but requires the creation of a specific environment. In nature, spawning occurs once a year, usually in June or July. The male prepares a spawning site by digging a depression under a rock or pebble, where eggs are laid after courtship. To stimulate spawning, it is recommended to simulate seasonal changes, including periods with cooler water and increased current. Fry develop within the substrate, feeding on microorganisms and organic detritus.

Fish are sensitive to water quality and dissolved oxygen levels, so keeping them in immature or poorly filtered aquariums often leads to weakened immunity. Secondary bacterial infections, developing against the background of parasitic infestations caused by stress during transportation or unsuitable conditions, are characteristic. Prevention involves maintaining high aeration, stable water parameters, and avoiding sharp temperature fluctuations.

When purchasing, choose active individuals that move confidently across hard surfaces using their sucker mouth. Avoid fish with signs of emaciation, sunken bellies, or skin damage, as the recovery of weakened specimens is extremely difficult. In the store, it is important to assess the overall cleanliness of the aquarium and ensure that the fish are kept with sufficient current, as prolonged stay in stagnant water negatively affects their health.