Floating blenny (Aspidontus dussumieri) also known as the Lance blenny and as Dussumier's blenny

The Floating blenny (Aspidontus dussumieri) is also known as the Lance blenny and as Dussumier’s blenny.  They were first described by Valenciennes in 1836 and were named after Jean-Jacques Dussumier a French naturalist who put together a large collection of species which were later studied and described by Achille Valenciennes and others.  Their common name Floating blenny comes from their habit of floating in current a few feet above the substrate. They seem to cover quite large distances floating with the current when they exhibit this behavior.

Floating blenny (Aspidontus dussumieri) also known as the Lance blenny and as Dussumier's blenny

 
APPEARANCE

The Floating blenny has a typical blenny shape with an elongated tubular body with a blunt rounded head.  The mouth is on the bottom of the head as with other similar looking blennies. They are capable of lightning and darkening their colors depending on mood and the background. Generally they have a white body with a blackish line along the mid body going up to the eye . When exhibiting the floating behavior their background color seems to be more brownish rather than white as can be seen in the images. Larger adults have a yellow tail with two long thin filaments that trail behind the fish .  On some of the sub adults the line across  the body is broken up in squares rather than being a line. They do look similar to the False cleaner wrasse but these have a sharper nose.

Floating blenny (Aspidontus dussumieri) also known as the Lance blenny and as Dussumier's blenny

FLOATING BLENNY IN THE WILD

The Floating blenny is usually found over coral reef ranging from 10 meters down to at least 25 meters. They are usually solitary but we have seen them in groups of up to 10 during spring with the males ( presumably) showing off their fins. They are usually very shy and head into small holes from which they will observe one. When seen floating along the reef in the current they seem to lose their usually shy behavior and make sure they stay a safe distance but just float along .  They seem to float long distances but for what purpose is unknown.

Floating blenny (Aspidontus dussumieri) also known as the Lance blenny and as Dussumier's blenny

HABITAT

The Floral blenny occurs throughout the Indo- West Pacific, from the East African Coast and Red Sea, to Japan in the north and down to New Caladonia.  They are usually found above 10 meters in the sub tidal zone, which is close to shore and always submerged. Thy always have several hiding places or holes close by.

Floating blenny (Aspidontus dussumieri) also known as the Lance blenny and as Dussumier's blenny

DIET

They feed  on algae and detritus  by using the lower jaw to bite onto the algae while the upper jaw (with the comb like appendages) scrapes algae into its mouth.

Floating blenny (Aspidontus dussumieri) also known as the Lance blenny and as Dussumier's blenny

REPRODUCTION

We have observed what appeared to be mating behavior with a group of some 10 fish  swimming around each other and with the larger specimens with yellow tendrils on the dorsal showing off displaying their fins. Other than this not much appears to be known of their mating habits.

Floating blenny (Aspidontus dussumieri) also known as the Lance blenny and as Dussumier's blenny

AQUARIUMS

They are not generally kept by  aquarists and are not common in the trade.

FLOATING BLENNY CLASSIFICATION

Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Blenniiformes
Family: Blenniidae
Genus: Aspidontus
Species: A. dussumieri

LITERATURE CITED

https://www.fishbase.se/summary/Cirripectes-castaneus