Luidia
Encyclopedia
Luidia is a genus
of starfish in the family
Luidiidae (Sladen
, 1889) in which it is the only genus. Members of the family have a cosmopolitan distribution
.
do not have suckers but have two swollen regions. There is a mouth, oesophagus and cardiac stomach but no pyloric stomach or anus. The gonad
s are underneath the sides of each arm.
The early larva
l stages of starfish are known as bipinnaria
larvae and members of this genus do not continue their development after this stage into a brachiolar stage before undergoing metamorphosis
. However, they are capable of larval cloning
, with asexual reproduction
taking place while they are larvae. This has been shown to take place both in the field and in laboratory cultures and has been studied by molecular analysis of sequences
of mitochondrial tRNA
to identify the taxa
involved.
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 starfish 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...
Luidiidae (Sladen
Percy Sladen
-Life and work:The son of a wealthy leather merchant, Sladen was born near Halifax, Yorkshire on 30 June 1849. He was educated at Hipperholme Grammar School and Marlborough College, but received no university training. As a young man he indulged his hobby of natural history, but soon become...
, 1889) in which it is the only genus. Members of the family have a cosmopolitan distribution
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...
.
Characteristics
Members of the genus are characterised by having long arms with pointed tips fringed with spines. The upper surface is covered with paxillae, pillar-like spines with flattened summit covered with minute spinules. There are no upper marginal plates, these being replaced by paxillae, but the lower marginal plates are large and themselves covered with paxillae. The tube feetTube feet
Tube feet are the many small tubular projections found most famously on the oral face of a sea star's arms, but are characteristic of the water vascular system of the echinoderm phylum which also includes sea urchins, sand dollars and sea cucumbers and many other sea creatures.Tube feet function in...
do not have suckers but have two swollen regions. There is a mouth, oesophagus and cardiac stomach but no pyloric stomach or anus. The gonad
Gonad
The gonad is the organ that makes gametes. The gonads in males are the testes and the gonads in females are the ovaries. The product, gametes, are haploid germ cells. For example, spermatozoon and egg cells are gametes...
s are underneath the sides of each arm.
The early larva
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
l stages of starfish are known as bipinnaria
Bipinnaria
A bipinnaria is the first stage in the larval development of most starfish, and is usually followed by a brachiolaria stage. Movement and feeding is accomplished by the bands of cilia. Starfish that brood their young generally lack a bipinnaria stage, with the eggs developing directly into...
larvae and members of this genus do not continue their development after this stage into a brachiolar stage before undergoing metamorphosis
Metamorphosis
Metamorphosis is a biological process by which an animal physically develops after birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation...
. However, they are capable of larval cloning
Clone
-Biological:* Clone—In biology and agriculture, any organism whose genetic information is identical to that of a parent organism from which it was created; natural reproductive processes producing clones include parthenogenesis and apomixis...
, with asexual reproduction
Asexual reproduction
Asexual reproduction is a mode of reproduction by which offspring arise from a single parent, and inherit the genes of that parent only, it is reproduction which does not involve meiosis, ploidy reduction, or fertilization. A more stringent definition is agamogenesis which is reproduction without...
taking place while they are larvae. This has been shown to take place both in the field and in laboratory cultures and has been studied by molecular analysis of sequences
DNA sequencing
DNA sequencing includes several methods and technologies that are used for determining the order of the nucleotide bases—adenine, guanine, cytosine, and thymine—in a molecule of DNA....
of mitochondrial tRNA
Transfer RNA
Transfer RNA is an adaptor molecule composed of RNA, typically 73 to 93 nucleotides in length, that is used in biology to bridge the three-letter genetic code in messenger RNA with the twenty-letter code of amino acids in proteins. The role of tRNA as an adaptor is best understood by...
to identify the taxa
Taxon
|thumb|270px|[[African elephants]] form a widely-accepted taxon, the [[genus]] LoxodontaA taxon is a group of organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement...
involved.
Species
The following species are recognised by the World Register of Marine Species (WoRMS):- Luidia alternata (Say, 1825)
- Luidia amurensis Doderlein, 1920
- Luidia armata Ludwig, 1905
- Luidia aspera Sladen, 1889
- Luidia asthenosoma Fisher, 1906
- Luidia atlantidea Madsen, 1950
- Luidia australiae Doderlein, 1920
- Luidia avicularia Fisher, 1913
- Luidia barbadensis Perrier, 1881
- Luidia bellonae Lütken, 1865
- Luidia changi Liu, Liao & Li, 2006
- Luidia ciliarisLuidia ciliarisLuidia ciliaris or the seven armed starfish is a species of starfish in the family Luidiidae. It is found in the eastern Atlantic Ocean and the Mediterranean Sea.-Description:...
(Philippi, 1837) - Luidia clathrata (Say, 1825)
- Luidia columbia (Gray, 1840)
- Luidia denudata Koehler, 1910
- Luidia difficilis Liu, Liao & Li, 2006
- Luidia ferruginea Ludwig, 1905
- Luidia foliolata (Grube, 1866)
- Luidia gymnochora Fisher, 1913
- Luidia hardwicki (Gray, 1840)
- Luidia herdmani A.M. Clark, 1953
- Luidia heterozona Fisher, 1940
- Luidia hexactis H.L. Clark, 1938
- Luidia inarmata Doderlein, 1920
- Luidia integra Koehler, 1910
- Luidia latiradiata (Gray, 1871)
- Luidia lawrencei Hopkins & Knott, 2010
- Luidia longispina Sladen, 1889
- Luidia ludwigi Fisher, 1906
- Luidia maculata Müller & Troschel, 1842
- Luidia magellanica Leipoldt, 1895
- Luidia magnifica Fisher, 1906
- Luidia mauritiensis Koehler, 1910
- Luidia neozelanica Mortensen, 1925
- Luidia orientalis Fisher, 1913
- Luidia patriae Bernasconi, 1941
- Luidia penangensis de Loriol, 1891
- Luidia phragma H.L. Clark, 1910
- Luidia porteri A.H. Clark, 1917
- Luidia prionota Fisher, 1913
- Luidia quinaria von Martens, 1865
- Luidia sagamina Doderlein, 1920
- Luidia sarsiLuidia sarsiThe Luidia sarsi is a species of starfish. Sand colored with a velvety texture, the species expresses pentamerism or pentaradial symmetry as adults. The five gently tapering arms have conspicuous bands of long white marginal spines in groups of three...
Düben & Koren, 1845 - Luidia savignyi (Audouin, 1826)
- Luidia senegalensis (Lamark, 1816)
- Luidia sibogae Doderlein, 1920
- Luidia superba A.H. Clark, 1917
- Luidia tessellata Lutken, 1859
- Luidia yesoensis Goto, 1914