Aplysia dactylomela
Encyclopedia
Aplysia dactylomela, common name
Common name
A common name of a taxon or organism is a name in general use within a community; it is often contrasted with the scientific name for the same organism...

 the "spotted sea hare", is a species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 of large sea slug
Slug
Slug is a common name that is normally applied to any gastropod mollusc that lacks a shell, has a very reduced shell, or has a small internal shell...

, a marine
Marine (ocean)
Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine ecology and marine geology...

 opisthobranch gastropod mollusc in the family Aplysiidae
Aplysiidae
The superfamily Aplysioidea is a superfamily of mostly rather large sea slugs, marine gastropod mollusks in the clade Aplysiomorpha within the informal group Opisthobranchia.This superfamily contains only one family, the Aplysiidae; the sea hares...

, the sea hares.

Distribution

This species of sea hare is cosmopolitan
Cosmopolitan distribution
In biogeography, a taxon is said to have a cosmopolitan distribution if its range extends across all or most of the world in appropriate habitats. For instance, the killer whale has a cosmopolitan distribution, extending over most of the world's oceans. Other examples include humans, the lichen...

, being found in almost all tropical and temperate seas, including recently the Mediterranean Sea
Mediterranean Sea
The Mediterranean Sea is a sea connected to the Atlantic Ocean surrounded by the Mediterranean region and almost completely enclosed by land: on the north by Anatolia and Europe, on the south by North Africa, and on the east by the Levant...

.

Description

The colour of the spotted sea hare is very variable, from pale gray to green, to dark brown. There are almost always large black rings on the mantle
Mantle (mollusc)
The mantle is a significant part of the anatomy of molluscs: it is the dorsal body wall which covers the visceral mass and usually protrudes in the form of flaps well beyond the visceral mass itself.In many, but by no means all, species of molluscs, the epidermis of the mantle secretes...

.

The maximum recorded length is 410 mm.

Habitat

Aplysia dactylomela is commonly found in shallow waters, tide pools and rocky and sandy substrates, they also will be found feeding in beds of sea grass. During the day they will mostly hide under large rocks and in crevices. They usually stay in relatively shallow water, but they have been found as deep as 40 m.

Minimum recorded depth is 0 m. Maximum recorded depth is 3 m.

Human use

The right giant neuron
Neuron
A neuron is an electrically excitable cell that processes and transmits information by electrical and chemical signaling. Chemical signaling occurs via synapses, specialized connections with other cells. Neurons connect to each other to form networks. Neurons are the core components of the nervous...

 of Aplysia dactylomela, which is found in the abdominal ganglion, is similar to that of vertebrates, meaning it is ideal for the study of electrophysiology
Electrophysiology
Electrophysiology is the study of the electrical properties of biological cells and tissues. It involves measurements of voltage change or electric current on a wide variety of scales from single ion channel proteins to whole organs like the heart...

, as well as conditioned-response studies. These neurons have been found to be invaluable in neurological research; the reason for this is that long lasting effects in neuronal behavior can be detected.

Behaviour

The Aplsia dactylomela is capable of swimming and crawling. It accomplishes the former by creating a funnel using the parapodia folded forward and downwards; this action pulls in water. It then pushes the water out from behind the animal by pressing the anterior parts of the parapodia together, thus forward motion is achieved.

The sea hare's usual mode of propulsion is crawling; it crawls by lifting the front end of the foot, stretching it forward then placing it on the ground in front, creating an arching pattern; the remainder of the body follows this arching pattern until the tail is reached.

Defence

Like the octopus, the Aplysia dactylomela squirts purple ink if it is disturbed; this ink is an irritant that causes 'altered behaviour' in other invertebrates and fish. Their leathery skin contains toxin
Toxin
A toxin is a poisonous substance produced within living cells or organisms; man-made substances created by artificial processes are thus excluded...

s which make this sea hare practically inedible to most predators.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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