Notarchus is a genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of 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...

s or sea hare

Sea hare

The clade Aplysiomorpha, commonly known as Sea hares or Sea Bags , are medium-sized to very large Opisthobranchia with a soft internal shell made of protein...

s, 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 mollusks in the family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 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.

Description

The parapodia (fleshy winglike outgrowths) of Notarchus are almost completely fused, forming the parapodial cavity.

Life habits

These sea hares are able to swim by jet propulsion, through sucking in water through the small anterior opening of the parapodial cavity and then squirting water from the back of it. While doing so, they tumble and make a series of backward somersaults. In this unusual manner, they move quickly out of harm’s way over short distances.

Species

Species within the genus Notarchus include:

• Notarchus indicus Schweigger, 1820 : Indian sea hare
  • Distribution : in shallow waters of NW Indian Ocean
    Indian Ocean
    The Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...
    
    , NW Pacific, Mediterranean.
  • Description : fine papillae scattered over the mantle; no armed penis; feeds on green alga Caulerpa
    Caulerpa
    Caulerpa is a genus of seaweeds in the family Caulerpaceae . They are unusual because they consist of only one cell with many nuclei, making them among the biggest single cells in the world...
    
    .
• Notarchus punctatus Philippi, 1836
  • Distribution : Japan
    Japan
    Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
    
    , Indo-Chinese seas, Mediterranean.
  • Length : 5 cm
  • Description : penis with spines.

External links

• Image of Notarchus indicus
• Images of Notarchus punctatus