Tag Archive: eels

Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii (ray-finned fishes)
Order: Anguilliformes (Eels and morays)
Family: Congridae (Conger and garden eels)
Subfamily: Heterocongrinae

Genus/species: Heteroconger hassi

GENERAL CHARACTERISTICS: The color is variable with tiny spots covering the body including three large black spots, two of which are usually visible. The third spot is on the anus, which is usually in the burro. The pectoral fins are minute.

Length up to 40 cm (16 in), body diameter of about 14 mm (1/2 in)

SPOTTED GARDEN EEL Heteroconger hassi FAM (Congridae) ,IMG_0193_2

DISTRIBUTION/HABITAT: Tropical Indo-Pacific: Red Sea and East Africa to the Society Islands. Found on sandy bottoms with some current near a reef at depths of 7–45 m (22-140 ft).

DIET IN THE WILD:  H. hassi feeds on microscopic animals in the water column.

REPRODUCTION: During mating season, males and females move their burrows closer together. With tails remaining in their burrows, they meet and entwine bodies. Males defend the females they have chosen. After mating the fertilized eggs are released into the current and float near the surface in the open ocean. The eggs hatch out and the larvae float until the eels are large enough to swim down and make a burrow.

Heteroconger hassi3302264315_77ea9161f9_b


REMARKS: Garden eels are usually found in colonies containing up to several hundred. The garden eel drives its pointy tail into the sand to create a burrow. Secretions from the skin harden and stabilize burrow sides. Part of the eel’s body remains in the burrow as it faces the current to feed. When approached, the animal withdraws into its burrow for protection.


California Academy of Sciences Steinhart Aquarium Hidden Reef 2018

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EOL eol.org/pages/205986/hierarchy_entries/44704953/details

Georgia Aquarium animalguide.georgiaaquarium.org/home/galleries/tropical-d…

Kingdom: Animalia
Phylum: Chordata
Superclass: Osteichthyes
Class: Actinopterygii (ray-finned fishes)
Order: Gymnotiformes (Knifefishes)
Family: Gymnotidae (Naked-back knifefishes)

Genus/species: Electrophorus electricus

GENERAL CHARACTERISTICS: This eels (knifefishes) body is elongated and cylindrical, almost without scales; head flattened; mouth large with one row of conical teeth on each jaw; presence of three abdominal pairs of electric organs. The color is dark with anterior ventral part yellowish. They have a very long anal fin.

Large up to 2.5 m (8 feet). Weight up to 20 kg (44 pounds)


DISTRIBUTION/HABITAT: Tropical. Amazon Basin: Orinoco, and related areas in northern South America. Found in lowland backwaters and muddy river bottoms, never fast-flowing waters. During daylight, retreats to recessed hiding places shared with conspecifics.

DIET IN THE WILD: E. electricus juveniles eat invertebrates such as shrimp; adults prey on fish and small mammals.

MORTALITY/LONGEVITY: Life span: in captivity males to 15 years, females to 20+


REPRODUCTION: E. electricus  males construct foam nests and guard the growing larvae. First-born larvae prey on other eggs and embryos coming from late spawning batches. In mid-January when the first seasonal rains flood the breeding area, causing the about 10 cm long young eels to disperse.

REMARKS: NOT A TRUE EEL. True eels lack pectoral and pelvic fins. Unlike “true” eels in the Order Anguilliformes, they are obligate air breathers, taking up to 80% of their oxygen directly from the air, an adaptation for survival in poorly oxygenated water. The long undulating anal fin allows the electric eel to move backwards or forwards.

Though not an aggressive fish, can produce enough voltage to severely injure humans. If an electric eel fires a series of charges, each successive charge is less powerful. Aquarists stimulate several discharges before attempting to handle the animal safely. These eels also have two other, much smaller sets of electric organs, used for orientation, finding prey.
Active nocturnally.

The long undulating anal fin allows the electric eel to move backwards or forwards. About half the musculature has been converted into electric organs which produce up to 650 V. These eels use their electricity to stun the fish they prey upon, as well as for defense.

As the eel (knifefish) matures it develops cataracts leading to blindness relying only on its electrical senses. (Similar to the elephant fish with poor vision).

CONSERVATION: IUCN Red List; Least Concern.


California Academy of Sciences Steinhart Aquarium Flooded Amazon 2018

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Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Anguilliformes (Eels and morays)
Family: Muraenidae (Moray eels)

Gymnothorax mordax 

GENERAL CHARACTERISTICS: Color is dark brown to green, mottled. The is somewhat compressed and has no pectoral fins
(all eels lack pelvic fins)..

Length up to 1.5 m (5 ft)

DISTRIBUTION AND HABITAT: Found from Point Conception to south Baja California in rocky subtidal areas diurnally resting in crevices or holes with their head usually protruding. Depth 6–40 m, typically 0.6–20 m.

DIET IN THE WILD: Feeds nocturnally upon crustaceans, octopuses and fishes. Prey is detected by smell.

MORTALITY/LONGEVITY: They can live up to 30 years.


REMARKS: Morays constantly open and close their mouth. They do this to aid respiration. It is not a threat display. California Moray bites can cause serious lacerations, and may be unprovoked.

Much of its time they hiding in holes and crevices amongst the rocks on the ocean floor. They are able to remain out of sight from predators and are also able to ambush any unsuspecting prey that passes.

California Morays may be eaten but some species of Moray are poisonous.


California Academy of Sciences, Steinhart Aquarium 2017

Pacific Coast Fishes Eschmeyer, Herald and Hammann page 64

More Than You Want To Know About The Fishes of the Pacific Coast, Milton Love 1996 pages 83-84

Animal Diversity Web animaldiversity.org/accounts/Gymnothorax_mordax/

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Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii (ray-finned fishes)
Order: Anguilliformes (Eels and morays)
Family: Congridae (Conger and garden eels)
Subfamily: Heterocongrinae

Genus/species: Gorgasia preclara

GENERAL CHARACTERISTICS: Its yellow to orange with characteristic white bands body has a circular shape with a diameter of about 10 mm (0.4 in). Length up to 40 cm (15.75 in) maximum.
Typically, only its head and upper body protrudes from the sand where the garden eel lives in a buried tube in the sand either alone or in small groups.

Garden Eel20776620435_68e152af6d_k

DISTRIBUTION/HABITAT: Found in the Indo-West Pacific in sandy areas exposed to currents at depths between 18 and 75 m (60-245 ft), but is usually observed at an average depth of 30 m (100 ft).




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California Academy of Sciences Water is life Exhibit 8-20-15

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Kingdom:  Animalia
Phylum:  Chordata
Class:  Actinopterygii (ray-finned fishes)
Order:  Perciformes (Perch-likes)
Family:  Anarhichadidae (Wolffishes)

Genus/Species:  Anarrhichthys ocellatus

An eel-like fish (large, elongate, compressed body) with no pelvic fins. Large pectoral fins. Colored mostly gray to brown, occasionally greenish. Round dark spots with pale rings on body and fins. Length to 2.4 m (7.2 ft). Weight to 18 kg 41 lb. Not a true eel of the Order Anguilliformes.

Sea of Japan and Aleutian Islands to Imperial Beach, California. Adults live on bottom, usually among rocks in subtidal locations; often in dens.

Crabs, sand dollars, marine snails and fishes.

Both male and female wrap their body around the egg mass to keep the eggs in place and to deter predators .

Predators of eggs include benthic rockfish and kelp greenlings.

REMARKS: Can inflict a painful bite. An edible food fish

LOCATION: California Rocky Coast CC06

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PHYLUM  Chorada

CLASS     Actinopterygii (ray-finned fishes)

ORDER    Anguilliformes (Eels and morays)

FAMILY    Muraenidae (Moray eels)

GENUS/SPECIES   Gymnothorax favagineus



This diverse group is noted for large mouths with numerous teeth, small gill openings, and the absence of pectoral and pelvic fins.  The anal and dorsal fins extend along much of the body and are continuous with the caudal fin. Gill openings are small and roundish and situated on the side of the head.

G. favagineus grows to 3 m, thus it is one of the two largest of Indo-Pacific moray eels. Spots variable between individuals and size.  The surface is covered with dark spots the size of their eye that form a honeycomb pattern. Some individuals colored almost totally black (those found in turbid water).    



Red Sea, East. Africa to Papua, New Guinea and Great Barrier Reef.  Usually rests in  reef flat rubble and outer reef slopes of  continental reefs, 1–45 m (3-150) in depth. Often found in crevasses with cleaner wrasses or cleaner shrimps.

                                   PHOTO BELOW: Symbiotic relationship with a cleaner shrimp.  


Predator upon cephalopods, crustaceans and small fishes.



Leptocephalus larvae.



Dark Cluster  PR22  



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Actinopterygii (ray-finned fishes),  Anguilliformes (Eels and morays),  Muraenidae (Moray eels)

Rhinomuraena quaesita

DISTRIBUTION: Indo-Pacific from East Africa to the Tuamota Archipelago (French Polynesia).

HABITAT: Lagoons and associated reefs at depths up to 57 m.

APPEARANCE: Long thin body and high dorsal fins. Has three fleshy tentacles on the tip of its lower jaw, a single fleshy pointed projection at the tip of its snout, and tubular anterior nostrils ending in gaudy, fanlike expansions. Juveniles are black with a yellow dorsal fin, males are mostly blue, and females are mostly yellow. Length up to 130 cm (51 in).

DIET: Mostly small fishes, some invertebrates.

REPRODUCTION and DEVELOPMENT: External fertilization nonguarder.  R. quaesita is a protandrous hermaphrodite, i.e., functioning males reverse sex to become females.  It is the only moray that undergoes abrupt changes in coloration and sex.  Protandry is diagnosed based on coloration, but not confirmed.

MORTALITY/LONGEVITY May have lifespan up to 20 years.

REMARKS: The ribbon eel buries itself in sand or hides in rocks or reefs, sometimes with head protruding, lying in wait or emerging to hunt for small fish. Like all morays, it rests with mouth open, displaying sharp teeth that appear ready for use. Actually, ribbon eels are among the least aggressive of morays, the gaping mouth simply aiding breathing by allowing oxygenated water to enter and pass over the gills.

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