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Masui's Shrimpgoby

Amblyeleotris masuii

A small marine goby that shares a fascinating symbiotic relationship with snapping shrimps of the genus Alpheus. It constantly watches for predators with its large, alert eyes.

Taxonomy
Class:Actinopteri
Order:Perciformes
Family:Gobiidae
Subfamily:Gobiinae
Genus:Amblyeleotris
Species:Amblyeleotris masuii

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Water Temperature

22 - 26 °C

pH Value

8.1 - 8.4

Water type

Marine

Tank level

Bottom

Adult size

11 cm

Minimum tank volume

>= 100 L

Minimum group

>= 1

Species description

Geographical Origin and Habitat: Masui's Shrimpgoby is native to the Northwestern Pacific Ocean, particularly around the southern coasts of Japan and the Ryukyu Islands. It inhabits sandy and muddy slopes as well as rubble zones near coral reefs, typically at depths ranging from 10 to 35 meters where it can find appropriate shelter.
Taxonomy and Morphology: Belonging to the class Actinopterygii, order Gobiiformes, and family Gobiidae, this species is classified under the genus Amblyeleotris. It features a slender, elongated body, large upward-staring eyes, and a broad mouth. Adults reach a maximum size of approximately 11 cm in length.
Social Behavior: This goby is famous for its mutualistic relationship with alpheid snapping shrimps (especially Alpheus bellulus). The shrimp excavates and maintains a shared sandy burrow, while the goby acts as an alert lookout, communicating threats via tail flicks to the nearly blind shrimp.
Coloration and Sexual Dimorphism: The body features a pale whitish or beige background color, intersected by broad vertical reddish-brown bands. The head and dorsal fins are adorned with numerous small yellow or orange spots. There is no major sexual dimorphism, though mature males may possess slightly larger fins.

Care, breeding and tankmates

Aquarium Setup: Requires a marine tank of at least 100 liters. A deep sand bed of fine grain (about 5-7 cm) is essential to facilitate the burrowing activities of its symbiotic shrimp. Aquascaping rocks must be placed securely on the bottom glass to prevent collapses due to excavation.
Diet and Feeding: Carnivorous. In captivity, it should be offered fine frozen foods such as mysis, brine shrimp, copepods, and finely chopped seafood placed near the burrow. It will also accept high-quality sinking marine pellets once acclimated to dry foods.
Water Quality: Keep water parameters stable: temperature 22°C to 26°C, pH between 8.1 and 8.4, and specific gravity around 1.020 to 1.025. High water quality with efficient protein skimming and moderate water flow is required to keep dissolved waste low.
Compatibility and Cohabitation: Extremely peaceful toward open-water tankmates. It is highly recommended to keep it with an Alpheus partner shrimp. Avoid large predatory fish, aggressive bottom-dwellers, and competitive species that might outcompete it for food or threaten its safety.
Aquarium Breeding: Spawning in home aquariums is very rare and challenging. Eggs are laid inside the safety of the burrow and guarded by the pair. The resulting larvae undergo a planktonic stage, making them exceptionally difficult to raise without specialized live micro-foods.
Risks and Diseases: The greatest risk is jumping out of the aquarium when startled, necessitating a tight-fitting lid or mesh cover. It is also vulnerable to starvation if housed with highly active, fast-swimming tankmates that consume all the food before it reaches the bottom.

Geographic Origin and Distribution

Masui's Shrimpgoby is native to the Northwestern Pacific Ocean, particularly around the southern coasts of Japan and the Ryukyu Islands. It inhabits sandy and muddy slopes as well as rubble zones near coral reefs, typically at depths ranging from 10 to 35 meters where it can find appropriate shelter.

Origin

Tropical oceans and reefsEast Asia

Fish profile

Temperament
Territorial
It is a peaceful, shy, and cautious fish that prefers to stay close to the safety of its established burrow. While it will bravely defend its immediate territory from other bottom-dwellers, it ignores fish swimming higher up. Providing plenty of rubble and a quiet environment helps it feel secure and behave naturally.
Diet
Carnivore
As a micro-predator, its natural diet consists mostly of tiny benthic crustaceans and zooplankton found near the substrate. In captivity, it eagerly accepts frozen mysis shrimp, brine shrimp, and sinking carnivore pellets. Providing a varied, high-quality meaty diet is critical for maintaining its health and vibrant coloration.
Sex ratio
Flexible
There are no obvious external differences between males and females, making sexing this species visually almost impossible. They are best kept singly or as a confirmed mated pair to avoid territorial disputes. Placing multiple unsexed individuals in a small tank usually leads to aggressive territorial battles over burrow sites.
Feeding frequency
Twice daily
Feeding small portions two to three times daily is recommended to mimic its natural, continuous foraging behavior. Because it rarely ventures far from its burrow, targeted feeding near its home may be necessary in a busy tank. Care should be taken to ensure it gets enough food without overfeeding the entire system.
Bioload
This species has a minimal impact on the overall bioload of the aquarium due to its small size and sedentary lifestyle. It produces very little waste compared to more active, open-water swimmers. Routine maintenance and standard filtration are entirely sufficient to keep the water pristine.
Flow
Strong
It favors gentle to moderate water flow, reflecting the calm sandy bottoms and rubble zones it inhabits in the ocean. Exceedingly strong currents can collapse its delicate burrow and make feeding difficult. A well-planned, indirect flow pattern allows the goby to thrive while keeping detritus from accumulating.
Jump risk
Yes
Like most gobies, this fish is easily spooked and possesses a strong instinct to jump when frightened or chased. A tight-fitting lid or a fine mesh cover is absolutely necessary to prevent it from leaping out of the aquarium. Keeping it in an open-top tank is highly risky and often ends poorly.
Reproduction
Oviparous
Captive breeding of this species is extremely rare and technically demanding, primarily due to the difficulty of raising its microscopic pelagic larvae. In their natural habitat, they are substrate spawners that lay adhesive eggs deep within the safety of their burrow. The male takes on the responsibility of guarding and oxygenating the eggs until they hatch.
Compatibility & tankmates
Community
It is a fantastic community fish for peaceful reef aquariums, coexisting easily with corals and small, non-aggressive tank mates. This fish forms a fascinating symbiotic bond with pistol shrimp, which provides an incredible behavioral display. Large or predatory fish must be avoided, as they will easily consume this small goby.
Tank level
Bottom
This bottom-dwelling fish spends the vast majority of its life resting on the sand bed or hovering just outside its burrow. It relies heavily on a deep sand substrate to create its home alongside its symbiotic shrimp partner. It will only dart higher into the water column momentarily to grab a passing morsel of food.

Window to the official scientific data of the species

Data synced on: 06/15/2026

Scientific Parameters & Models

Trophic level
3.4 ± 0.4 se
Resilience
High (less than 15 months)
Phylogenetic uniqueness (PD50)
0.5
Bayesian Length-Weight
a = 0.00741, b = 3.09
VulnerabilityLow vulnerability (10 / 100)

Image gallery

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

Related species

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Variants and close relatives

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

Banded-head Shrimpgoby

Banded-head Shrimpgoby

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Blackhead Shrimpgoby

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Delicate Shrimpgoby

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Diagonal-bar Shrimpgoby

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Downing's Shrimpgoby

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Ellipse shrimpgoby

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Amblyeleotris ellipse

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Giant prawn-goby

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Amblyeleotris fontanesii

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Harris's Shrimpgoby

Harris's Shrimpgoby

Amblyeleotris harrisorum

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Long-filament Shrimpgoby

Long-filament Shrimpgoby

Amblyeleotris macronema

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Marquesas Shrimpgoby

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Amblyeleotris marquesas

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Morishita's Shrimpgoby

Morishita's Shrimpgoby

Amblyeleotris morishitai

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Neumann's prawn-goby

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Amblyeleotris neumanni

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New Caledonia Shrimpgoby

New Caledonia Shrimpgoby

Amblyeleotris novaecaledoniae

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Red-banded Shrimpgoby

Red-banded Shrimpgoby

Amblyeleotris fasciata

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Redmargin shrimpgobid

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Amblyeleotris rubrimarginata

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Redspotted shrimpgoby

Redspotted shrimpgoby

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Similar care

Cards with similar requirements, difficulty, habitat, and husbandry profile.

Twin-spot Shrimpgoby

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Amblyeleotris biguttata

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Bleeker's Shrimpgoby

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Broadband Goby

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Naked-headed Shrimpgoby

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Periophthalma Shrimp Goby

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Randall's Shrimp Goby

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Amblyeleotris randalli

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Spotted-tail Shrimpgoby

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Yano's Shrimp Goby

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Neglected Shrimpgoby

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Aurora Goby

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Japanese shrimp goby

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Arch-fin shrimpgoby

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Amblyeleotris arcupinna

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Beautiful-cheek shrimpgoby

Beautiful-cheek shrimpgoby

Amblyeleotris callopareia

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Orange-spotted Prawn-goby

Orange-spotted Prawn-goby

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Steinitz' Goby

Steinitz' Goby

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Wheeler's watchman goby

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Last updated: 06/30/2026