Sicyopterus Stimpsoni: 21 Facts You Won’t Believe!

Sicyopterus stimpsoni facts this is a species of gobies endemic to Hawaii

Sicyopterus stimpsoni is a species of goby endemic to the Hawaiian islands. The fish is known by many different names like Nopoli rock climbing goby, Oopu Nopili, or Stimpson's goby. This fish is known to move around throughout its life. The uniquely shaped mouth helps the fish suck into the rock and climb. This feature helps to differentiate Stimpson's goby from other fishes. To climb, the fish uses the mouth and pelvic suckers repeatedly. After the juveniles climb back to their freshwater habitats, they live in the same place for a few years.

There are three species of waterfall climbing fishes native to Hawaii. Various other similar fishes are found in New Zealand, Iceland, Venezuela, Thailand, Japan, and Puerto Rico. The Hawaiian Stimpson's Goby is endemic to the island of Hawaii and only found in those regions.

For more relatable content, check out these tidewater goby facts and round goby facts.

Sicyopterus stimpsoni

Fact File

What do they prey on?

Algae, Insects, Red Slime Algae

What do they eat?


Average litter size?


How much do they weigh?


How long are they?

7.8 in (19.8 cm)

How tall are they?


What do they look like?

Blue, Red

Skin Type

Wet, Slimy Scales

What are their main threats?

Habitat Loss, Predators

What is their conservation status?

Near Threatened

Where you'll find them

Mountain Streams, Swift-Flowing Basalt-Bottomed Streams







Scientific Name

Sicyopterus stimpsoni





Sicyopterus Stimpsoni Interesting Facts

What type of animal is a Sicyopterus stimpsoni?

Stimpson's goby is a species of Goby endemic to Hawaii.

What class of animal does a Sicyopterus stimpsoni belong to?

Sicyopterus Stimpsoni falls under the class of Actinopterygii (ray-finned fishes) in the kingdom of Animalia.

How many Sicyopterus Stimpsonis are there in the world?

The population of these fishes is not known. They are threatened because of various reasons discussed below.

Where does a Sicyopterus stimpsoni live?

The Sicyopterus stimpsoni range is limited to freshwater streams and coastal waters of the Hawaiian Islands, only rare on Oahu.

What is a Sicyopterus stimpsoni's habitat?

The Sicyopterus stimpsoni habitat is mainly freshwater streams and brackish waters. They are only sometimes found in saltwater areas. Juveniles move from saltwater to freshwater depending on the benthic algae cycle. Adults require areas with clean gravel and rocks to facilitate the growth of algae on the rock surfaces.

The life cycle of these fishes includes moving up and down the streams throughout the season. They are found in depths up to 984.25 ft (300 m).

Who does Sicyopterus stimpsoni live with?

Usually found solitary or in small groups.

How long does a Sicyopterus stimpsoni live?

The Sicyopterus stimpsoni life span is around five or six years.

How do they reproduce?

Females are known to attach their eggs to the rocks after mating with the males. When the eggs hatch, they are immediately washed down to the sea. After they are developed in the sea habitat, the young swim and climb back to the freshwater pools.

The number of eggs is not known.

What is their conservation status?

The Sicyopterus stimpsoni distribution is only restricted to the Hawaiian islands. Therefore, these habitats are the only home for the fish. However, due to many natural phenomena like hurricanes and storms, there is frequent relocation for the goby. Also, the introduction of many predatory Ray-finned fishes in these habitats has reduced the numbers of the Sicyopterus stimpsoni quite a bit, leading to the conservation status of 'near threatened' by the IUCN Red List.

Sicyopterus Stimpsoni Fun Facts

What does Sicyopterus stimpsoni look like?

This image is of a fish in the family of Actinopterygii, the same family as Sicyopterus stimpsoni

*Please note that this is an image of a Sicyopterus lagocephalus, not a Sicyopterus stimpsoni. If you have an image of a Sicyopterus stimpsoni, please let us know at

The color in the body changes as per the life cycle and the seasons. Bright red and blue coloration can be seen during the breeding season and the goby changes according to their mood. This fish can easily be characterized by the dorsal fin. The male has an extended ray on the long first dorsal fin. When folded, it overlaps the second dorsal fin. The fish is usually seen as black when disturbed and the young are brown to grey-green speckled in coloration.

The body shape of Stimpson's goby differs quite a lot from the round goby as their body shape is quite big with a rounder head. The former has a more streamlined body and head.

How cute are they?

These fish are not usually considered cute.

How do they communicate?

Fish communicate by tactual methods and body movements.

How big is a Sicyopterus stimpsoni?

The Stimpson's goby has a range of length up to 7.8 in (19.8 cm).

The largest freshwater fish, beluga sturgeon, has a range in length up to 24 ft (731.5 cm). The species is native to the Caspian sea.

How fast can a Sicyopterus stimpsoni swim?

The swimming speed of Stimpson's goby is not available. They are known to swim a lot - for migrating and when their freshwater habitat is disturbed. The species is known to use its teeth to crawl up the waterfall to reach upstream.

How much does a Sicyopterus stimpsoni weigh?

The weight of these ray-finned fishes is not known.

The weight of the round goby, one of the other species of gobies, has a range of weight up to 0.2 lb (90.7 g).

The whale shark is the heaviest and the world's largest fish, with its weight going up to 29998-40000 lb (13606.8-18143.7 kg).

What are the male and female names of the species?

Males and females are not given different names.

What would you call a baby Sicyopterus stimpsoni?

A baby is called a juvenile.

What do they eat?

Adults are herbivores and feed only on diatoms and filamentous algae. They let the algae grow in rocks and cultivate from the gardens of diatoms, filamentous algae, and blue-green algae. Males protect their territories vigorously. Young sometimes feed on plankton and insects until they reach a mature age. The change in the position of the mouth while aging leads to the change in diet from omnivorous to herbivorous. They use the mouth as a sucker to climb the waterfalls too.

These fishes are preyed upon by birds like the black-crowned night heron. Stimpson's goby is also a food for many other ray-finned fishes like the great barracuda and the yellow thread threadfin. The Sicyopterus stimpsoni is killed by these predatory fishes when the fish moves up the stream during migration through the estuary.  

Are they poisonous?

There is no information on the poisonous nature of the goby.

There are around 2000 species of gobies and most of them are not poisonous. They are also eaten in a limited capacity by humans.

Would they make a good pet?

There is very limited information on these fishes as pets. However, they have been bred successfully in captivity.

Did you know...

Gobies are known to climb extremely high waterfalls to reach their adult habitats. They need to go through a stream full of predators. Even after all these tiring hurdles, it takes just three days for the gobies to climb these high waterfalls.

Different types of Stimpsoni

Apart from the Hawaiian Sicyopterus stimpsoni that we are discussing, there are several other Stimpsoni species in different families living in the world. They were all discovered by William Stimpson.

Conus stimpsoni is a type of venomous sea snail found in the Caribbean Sea from Florida to Yucatan in Mexico. This species is also known as Stimpson's cone.

Colus stimpsoni or Stimpson's colus is also a species of sea snail found in the Bay of Funday in Canada and also has its range of habitat in the western shore of Northern America.

Bathycongrus stimpsoni is a species of Eel and is found in Indonesia and Hawaii.

Solaster stimpsoni is a species of starfish found in the seas of Japan.

Heptacarpus stimpsoni or Stimpson Coastal Shrimp is found in the Eastern Pacific: Canada.

Stimpson's hard clam (Mercenaria stimpsoni) is native to Japan.

Eyespot Rock Shrimp or Sicyonia stimpsoni is a species of shrimp found in North Carolina, Gulf of Mexico, Antilles, and the Caribbean Sea.

Does Sicyopterus stimpsoni bite?

There is not much information if the Sicyopterus stimpsoni fishes bite. However, as the fishes have teeth, it is possible that they bite. Also, many species of gobies are aggressive and are known to bite.

Here at Kidadl, we have carefully created lots of interesting family-friendly animal facts for everyone to discover! Learn more about some other fish from our rainbow trout facts or pigfish interesting facts pages.

You can even occupy yourself at home by coloring in one of our free printable fish coloring pages.



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