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InvertebrateMarineBrackishEasy

Feeble shrimp

Palaemon debilis

Extremely adaptable to freshwater, brackish, or marine setups, this lively shrimp is a versatile scavenger. It requires an environment with complex hiding places like roots and marine macroalgae.

Taxonomy

Class:Malacostraca

Order:Decapoda

Family:Palaemonidae

Subfamily:Palaemoninae

Genus:Palaemon

Species:Palaemon debilis

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Water Temperature

20 - 28 °C

pH Value

7.8 - 8.4

Water type

Marine / Brackish

Invertebrate type

Marine shrimp

Adult size

3.5 cm

Minimum group

>= 4

8 - 12 dKH

Ecological role

Scavenger

Species description

Geographical Origin and Habitat: Palaemon debilis is widely distributed along the tropical and subtropical coasts of the Indo-Pacific. It is found from the Red Sea and East African coasts to the Hawaiian Islands, Ryukyu Islands, and French Polynesia. It primarily inhabits shallow coastal habitats with minimal or no current, such as mangrove forests, coastal lagoons, river estuaries, tide pools, and seagrass beds. As a highly euryhaline species, it is capable of surviving and thriving in fresh, brackish, and marine waters, even colonizing hypersaline coastal pools.

Taxonomy: It belongs to the class Malacostraca, order Decapoda, family Palaemonidae, and genus Palaemon. The physical structure is typical of palaemonid shrimps, characterized by a slender and flexible body with a well-developed, serrated rostrum on the head that is slightly curved upward. It reaches a total adult length usually ranging between 4 and 5 centimeters, with long, thin walking legs adapted for searching the substrate.

Social Behavior: It is a gregarious, shy but active species that feels secure when housed in groups of several individuals (at least 5-10 specimens). It exhibits completely peaceful behavior and shows no form of aggression or territoriality toward conspecifics or other tankmates. It spends the day walking on plants, rocks, and sand, tirelessly searching every crevice for organic remains.

Coloration and Sexual Dimorphism: The body is almost completely transparent or glassy, with thin dark or brownish longitudinal lines and small spots scattered on the claws and walking legs. This transparency serves as an extraordinary defense against predators. Adult females are easily distinguished from males as they are noticeably larger and, during the breeding season, carry a green or yellowish egg mass under their abdomen.

Care, breeding and tankmates

Tank Setup: Being extremely adaptable, it can be kept in freshwater, brackish, or marine aquariums with a minimum capacity of 30 liters. The tank must offer numerous hiding places made with rocks, driftwood, mangrove roots, or hardy plants like Anubias and Microsorum (in freshwater) or Caulerpa algae (in brackish/marine water). A fine sand or fine gravel substrate is ideal to allow it to walk without injury. It is advisable to use filter intakes equipped with a sponge cover to prevent the shrimps from being sucked in.

Diet and Feeding: It is an omnivorous scavenger. It actively consumes all types of detritus, leftover fish food, algae, and decaying organic matter. It readily accepts sinking pellets for fish or crustaceans, spirulina powder or flakes, and small pieces of frozen food like mysis or chopped krill. It never attacks fish or other live organisms, making it perfect for keeping the aquarium clean of decomposing organic matter.

Water Quality: It displays exceptional tolerance to water parameters. It can live in salinities from 0 (freshwater) to 35 ppt (marine water), although brackish conditions (salinity between 10 and 20 ppt, specific gravity 1.007-1.015) are ideal. The temperature should be maintained between 20°C and 28°C, with a stable pH between 7.5 and 8.2. It requires well-oxygenated water and, though very hardy, is sensitive to high levels of ammonia, nitrites, and especially copper, which must be strictly avoided.

Compatibility and Tankmates: It is compatible with small, peaceful fish suited to the same conditions, such as guppies and platies (in freshwater), or mollies and gobies (in brackish water), or tiny gobies and pipefish (in marine water). Co-habitation with medium-to-large predatory fish like cichlids, angelfish, large crustaceans, or predatory crabs should be strictly avoided, as they will easily hunt and consume it.

Aquarium Breeding: Breeding is possible and relatively easy in brackish or marine conditions. The female carries the fertilized eggs under her pleopods for about 2-3 weeks until they hatch. The released larvae are planktonic and require brackish or marine water rich in phytoplankton and rotifers to complete their larval molting stages before settling on the bottom as fully metamorphosed young shrimps. Breeding in pure freshwater is virtually impossible due to poor larval survival.

Risks and Diseases: The primary risk lies in issues related to shedding the exoskeleton, which can occur if the water is deficient in iodine, calcium, or magnesium. Regularly dosing these elements is recommended to promote proper calcification of the new shell. It is sensitive to heavy metal buildup in the water, especially copper, which is found in many fish medications. Another risk is thermal stress caused by sudden temperature shifts during water changes.

Geographic Origin and Distribution

Palaemon debilis is widely distributed along the tropical and subtropical coasts of the Indo-Pacific. It is found from the Red Sea and East African coasts to the Hawaiian Islands, Ryukyu Islands, and French Polynesia. It primarily inhabits shallow coastal habitats with minimal or no current, such as mangrove forests, coastal lagoons, river estuaries, tide pools, and seagrass beds. As a highly euryhaline species, it is capable of surviving and thriving in fresh, brackish, and marine waters, even colonizing hypersaline coastal pools.

Origin

Tropical oceans and reefsAfrica and MadagascarEast Asia

Invertebrate profile

Diet: Omnivore
Ecological role: Scavenger
Shock sensitivity: Medium
Calcium and minerals: High
Molting: Periodic
Reproduction: Oviparous
Compatibility & tankmates: Peaceful

Image gallery

Licensed images linked to the species or, when marked, to the closest representative taxon.

Related species

Recommendations grouped by close relatives, companion choices, and similar care.

Variants and close relatives

Same atlas type, nearby scientific identity, genus, or family.

Ghost Shrimp

Palaemon paludosus

Species description

Care, breeding and tankmates

Geographic Origin and Distribution

Origin

Invertebrate profile

Image gallery

Related species

Variants and close relatives

Ghost Shrimp

Daggerblade Grass Shrimp

Ditch Shrimp

Sargassum Shrimp

Emperor shrimp

Holthuis's Anemone Shrimp

Magnificent Anemone Shrimp

Sarasvati Anemone Shrimp

Starfish Shrimp

Urchin Shrimp

Bumblebee Shrimp

Anton Bruun's cleaner shrimp

Chocolate / Red rusty shrimp

Harlequin shrimp

Peacock anemone shrimp

Pederson's cleaner shrimp

Recommended companions

Two-spot bimaculatus blenny

Tailspot blenny

Striped fangblenny

Grape caulerpa

Caulerpa prolifera

Chaetomorpha macroalgae

Dead man fingers algae

Halimeda macroalgae

Red gracilaria

Beautiful Blenny

Blue assessor

Allen's blenny

Ambon Chromis

Axelrod's blenny

Black combtooth blenny

Black-axil Chromis

Similar care

Mangrove Hermit Crab

West African hermit crab

Boggess' Peppermint Shrimp

Padavensis Hermit Crab

Saron Shrimp

Anchisteus Cleaner Shrimp

Blue-legged Boxer Shrimp

Bluntclaw snapping shrimp

Crested snapping shrimp

Hammer Snapping Shrimp

Peppermint Shrimp var. multiscissa

Spotted cleaner shrimp

Edwards' Snapping Shrimp

African snapping shrimp

Anker's Cleaner Shrimp

Lipke's Cleaner Shrimp