1. of, like or pertaining to the depths of the ocean.

2. the collection of organisms living on or in sea or lake bottoms.

3. the bottom of a sea or lake; pertaining to the ecological region at the lowest level of a body of water such as an ocean or a lake.

Etymology: from Greek benthos “depth”; related to bathus “deep”.


Garden Eels. By: Jérôme C

These animals use their rigid tail-tip to dig a burrow in the sand. They exude lots of mucus from the skin that helps cement the sand grains together so the burrow walls become stable. If danger approaches, they withdraw into their burrows, but when the potential threat disappears, the garden eels reappear.


Agencia SINC

The maximum temperature which develops animal life is above 42 º C and below 50 ° C, according to the first study with worms Pompeii, who usually live in hydrothermal vents, cracks in the seafloor surface of the hot water coming out.

The worms, called Alvinella pompejana colonize the walls of chimneys that are created in the hydrothermal vents of the deep water and thrive in extreme conditions of temperature and pressure. 

Previous studies suggested that these worms could grow at temperatures of 60 ° C or more, but it has been found that it is not. ”Those previous works assumed that Alvinella was kind of emergency heat in the scientific world and it was agreed that 50 ° C was the limit for that animal life thrive," says Bruce Shillito, of the University Pierre and Marie Curie (UPMC, France) , and lead author of the research, published in the journal PLoS ONE.

According to their findings, prolonged exposure to temperatures of 50 ° C to 55 ° C causes lethal damage in tissue, which shows that in the wild these worms are not able to withstand long term exposure above 50 ° C.

However, the researchers also found that the optimum temperature for survival was still above 42 º C, ranking among the most familiar animals “heat lovers”.


The Self is no pearl, no breath-holder’s 
prize, no ornament salvaged from kelp 
and surface-borne, and bathed in light

as treasure swollen, bright and holy 
in the fleshy lap of life. No—

the self’s a thing that crawls,

cavern-deep and scuttle-limbed
through scattergrams of sand

which hang, suspended 
in the dim and stagnant depths
where it is hatched; 

where every oyster lies, dissected
on its back, The Self emerges: 

stiff, thoracic, from its jutting ledge
of rock, and learns to navigate

through hunger, trench-like 
blindness, skies of sand.

167. ANIMALS FIXED TO THE EARTH LIKE PLANTS: Sponges Rooted to the Sea-floor.

[There is one division that consists of] animals that remain perfectly fixed to the bottom or are capable only of creeping or crawling over the rocks and sand, such as the sponges, hydroids, sedentary tunicates, gasteropods, most lamellibranchs, and many crustacea. This portion of the fauna [of the sea] has been called the benthos.

— HICKSON Fauna of the Deep Sea, ch. 3, p. 53. (A., 1894.) 



Meiofauna (medium [sized] fauna) are small invertebrates that live either at the bottom of a body of water (“epifauna”) or just below it, burrowed into the sediment (“infauna”). There are both marine and freshwater meiofauna.

The term Meiofauna is not taxonomic. It’s a way of grouping bottom dwelling organisms by their size: larger than microfauna but smaller than macrofauna. In the field this means they can pass through a 1 mm mesh but will be retained by a 45 μm mesh, [Wikipedia]


[1] Darkfield photograph of a gastrotrich. Taken through a 10x ocular and 10x objective. [Source: Meiofauna of Eagle Cove] Not all gastrotrich are benthic.

[2][3] Live Ammonia tepida live benthic foraminiferan. [(2) collected from San Francisco Bay; phase-contrast photomicrograph by Scott Fay, UC Berkeley, 2005]

[4] Live planktonic foraminiferaGlobigerinella aequilateralis, from near the Bermuda Islands, showing extensive spine array, and pseudopodia running along them. [Source

[5] Example of meiofauna in Phylum Annelida: polychaete worms
[Source: Meiofauna of Eagle Cove]

[6] Example of meiofauna in Subclass Copepoda (Arthropoda: Crustacea: Maxillopoda). Copedpods are one of the most ubiquitous forms of animal life in the open ocean, but also a common component of meiofaunal communities. [Source: Meiofauna of Eagle Cove]

The giant Isopod, known scientifically as Bathynomus Giganteus, is the largest known member of the Isopod family. It is a carnivorous crustacean that spends its time scavenging the deep ocean floor. Food is extremely scarce at these great depths, so the Isopod has adapted to eat what ever happens to fall to the ocean floor from above. It will also feed on some of the small invertebrates that live at these depths.

(I can’t lie, it creeps me out. But in a good way!)


This tiny octopus weighs 45 grams on average and is smaller than your hand. It is a deep sea octopus, and this one in particular broods over its eggs for 400 days, wasting away as it feeds on itself to get energy. They live much longer than shallow water octopi as well, up to six years in some cases, rather than just one year.


Here’s some live footage of Benthos playing Memosa in Mt. Pleasant earlier this year! They’ll be playing with A Great Big Pile of Leaves, Mansions, Young Statues, and Vinacious on 3/24 at Mac’s Bar [Lansing]. This is going to be a show you won’t want to miss, so grab tickets now so you don’t forget! Fee-free tickets are available now at


Gifts from Enola - Benthos