''Arachnoides'' is a genus of

sea urchin Sea urchins () are spiny, globular echinoderms in the class Echinoidea. About 950 species of sea urchin live on the seabed of every ocean and inhabit every depth zone from the intertidal seashore down to . The spherical, hard shells (tests) of ...

within the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Clypeasteridae Clypeasteridae is a family of sea urchins in the order Clypeasteroida. This family was first scientifically described in 1835 by the Swiss-American biologist Louis Agassiz. Genera The World Register of Marine Species list the following genera as ...

, found in the

Indo-Pacific The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...

oceans. The base is flat and the upper surface is convex. If you are looking for a ''

fern A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The polypodiophytes include all living pteridophytes except t ...

'' genus, its name is Arachniodes.

Species

The

World Register of Marine Species The World Register of Marine Species (WoRMS) is a taxonomic database that aims to provide an authoritative and comprehensive list of names of marine organisms. Content The content of the registry is edited and maintained by scientific specialist ...

list the following species as being in this genus:- * ''

Arachnoides placenta ''Arachnoides placenta'' is a species of sea urchin of the family Clypeasteridae. Their armour is covered with spines. It is placed in the genus Arachnoides and lives in the sea. Arachnoides placenta was first scientifically described in 1758 b ...

'' ( Linnaeus,

1758 Events January–March * January 1 – Swedish biologist Carl Linnaeus (Carl von Linné) publishes in Stockholm the first volume (''Animalia'') of the 10th edition of Systema Naturae, 10th edition of ''Systema Naturae'', the sta ...

)

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

Philippines The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no), * bik, Republika kan Filipinas * ceb, Republika sa Pilipinas * cbk, República de Filipinas * hil, Republ ...

* ''

Arachnoides tenuis ''Arachnoides tenuis'' is a species of sea urchin of the family Clypeasteridae. Their armour is covered with spines. It is placed in the genus Arachnoides and lives in the sea. Arachnoides tenuis was first scientifically described in 1938 by Hube ...

'' H. L. Clark, 1938 Western Australia ''Arachnoides zelandiae'' Gray, 1855

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

: Synonym of ''

Fellaster zelandiae ''Fellaster zelandiae'', which is also called a cake urchin, or the snapper biscuit, is an echinoderm of the family Arachnoididae, endemic to New Zealand. The maximum width of this type of echinoderm An echinoderm () is any member of the ...

'' (Gray, 1855)

References

Natural History Museum
Clypeasteridae Echinoidea genera Echinoderms of Oceania Echinoderms of Asia {{echinoidea-stub