The Lawnmower Blenny, scientifically known as Salarias fasciatus, is a popular fish among marine aquarium enthusiasts, celebrated for its algae-eating capabilities. Also known as the Jewelled Blenny, Sailfin Blenny, or Algae Blenny, this fish belongs to the Blenniidae family, specifically the combtooth blennies. This article delves into the specifics of the Lawnmower Blenny's diet in an aquarium setting, addressing potential challenges and offering solutions for maintaining its health and well-being.
Lawnmower Blenny Basics
Lawnmower blennies share a similar body shape to other fish under the Blenniiformes order, sporting a long, torpedo-like appearance. They typically exhibit a tan coloration adorned with iridescent spots on the face and eyes, and a continuous dorsal fin that spans the length of the fish. Hobbyists can distinguish males from females by observing the spines on their anal fins, where females have two spines, one larger than the other.
These blennies are residents of tropical, shallow coastal habitats and are typically found on fringing reefs or on lagoon patch reefs and rubble patches. Salarias spp. are most often found at depths of less than 15 meters (50 feet). They regularly live among coral rubble, macroalgae, or branching stony corals or at the base of sponges.
Understanding the Lawnmower Blenny's Natural Diet
In their natural habitat, Lawnmower Blennies primarily feed on detritus and biofilm, along with algae. Recent studies have shown that detritus in the form of detrital aggregates constitutes a significant portion of their diet. They use their flexible jaws and comb-like teeth to pound the substrate, scraping off this material from hard surfaces such as coral rock and dead coral skeletons. Additionally, they may incidentally ingest tiny invertebrates.
The diet of Salarias fasciatus has been reported to include filamentous algae, diatoms, foraminiferans (shelled protozoa), tiny crustaceans, detritus, and sand. Occasionally, they may also consume fish eggs, sponges, and small snails. It's worth noting that they ingest a significant amount of calcium carbonate while feeding, which is common for herbivores with less selective feeding tactics.
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Challenges in Replicating the Natural Diet in Captivity
One of the most significant challenges in keeping Lawnmower Blennies in an aquarium is replicating their natural diet. Many hobbyists underestimate the amount of algae required to maintain a healthy appearance. While they may consume nutrient-rich flake and pellet food, as well as frozen foods like mysis and brine shrimp, they may lose interest in eating algae once they've tasted these new food sources.
Ensuring Adequate Algae Growth
To provide an adequate supply of algae, hobbyists should create an environment that encourages its growth. Lawnmower blennies are used to large amounts of rock, which play host to a variety of different types of marine algae. Hobbyists will want to form plenty of crevices and small caves using rock work for these fish to hide in. A mature tank of at least 55 gallons is recommended, as it provides ample surface area for algae to grow. Suppress the urge to scrub algae off every surface: your lawnmower blenny will do that for you.
Supplementing with Prepared Foods
While algae should be the primary food source, supplementing with prepared foods is often necessary, especially in tanks with limited algae growth. Algae-based foods specially formulated for herbivores, such as pellets or gel foods containing plenty of spirulina, are excellent options. You could also opt for blanched veggies like peas and spinach, or nori sheets.
Some reefers have found success with "Hikari Seaweed Extreme" for picky blennies. Nori sheets can be offered by placing them in a clip or rubber banding them to a small rock near the blenny's favorite hangout. It is important to select nori sheets that contain only seaweed, without any added salt or seasoning.
Observing Feeding Behavior
Feeding behaviors can vary between individual fish, so hobbyists need to monitor their Lawnmower Blenny's eating habits closely. If the blenny's belly appears pinched or its dorsal musculature looks thin, it may not be getting enough to eat. In such cases, increasing the amount of algae available or supplementing with more prepared foods may be necessary.
Read also: Aquarium Scooter Blenny Care
Addressing a Lawnmower Blenny's Reluctance to Eat
If a Lawnmower Blenny is not eating, several strategies can be employed to encourage it to feed:
- Introduce Nori Sheets: Place nori sheets in the tank, either using a clip or attaching them to a rock with a rubber band. Position the nori near the blenny's preferred spot.
- Offer a Variety of Foods: Try different types of algae-based foods, such as spirulina flakes or tablets, to see which ones the blenny prefers.
- Create a Natural Grazing Environment: Add more live rock to the tank to provide additional surfaces for algae to grow.
- Consider a Separate Algae Growing Container: Dedicated lawnmower blenny owners can grow algae in a separate container by keeping rocks under strong lighting to stimulate the growth of this aquatic delicacy!
Tank Size and Compatibility
A tank that is at least 55 gallons or more for one of the larger members of the genus. Smaller tanks may not have enough surface area to grow enough algae to sustain the blenny. Given a proper environment, the Lawnmower Blenny is relatively easy to care for. However, hobbyists should be aware of their dietary requirements. Lawnmower blennies should be drip acclimated, using a drip acclimation kit . Lawnmower blennies are used to large amounts of rock, which play host to a variety of different types of marine algae. Hobbyists will want to form plenty of crevices and small caves using rock work for these fish to hide in. A tight-fitting lid is a must, as these fish will jump out of an aquarium.
Lawnmower blennies are generally peaceful fish, but they can be territorial towards other blennies, especially those of the same species or similar size. Therefore, it is best to keep only one Salarias sp. per tank. They can be combined with most common reef fish, although it is best to avoid very docile species such as pipefish to prevent the blenny from bothering them.
Maintaining a Healthy Aquarium Environment
In addition to providing an adequate diet, maintaining a healthy aquarium environment is crucial for the well-being of Lawnmower Blennies. This includes:
- Stable Water Parameters: Regularly test and maintain stable water parameters, including temperature, pH, salinity, ammonia, and nitrite levels.
- Adequate Filtration: Use mechanical filters to remove detritus and suspended particles, which can improve water quality and provide a food source for the blenny.
- Regular Water Changes: Perform regular water changes to remove accumulated waste and replenish essential trace elements.
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