Protoreaster+nodosus

**Knobbly Sea Star** **//Protoreaster nodosus// (Linnaeus, 1758)**

**Common names** Knobbly Sea Star, Chocolate Chip Sea Star, Horned Sea Star, Rhinocerous Sea Star

=toc= =Biology = **Feeding habits** The Knobbly sea star feeds on microbial and microalgal films and detritus associated with the sediment surface, sea grasses or macroalgae (Scheibling & Metaxas, 2008). Opportunistic feeding on gastropods, sponges, soft corals, and other small invertebrates has also been observed by Schoppe (2000) 5]. Food is digested extraorally by everting its cardiac stomach upon the substratum (Scheibling & Metaxas, 2008). (See video below). media type="youtube" key="rE8l-KFQlhY" height="267" width="349" align="center"

Note: This video shows the general feeding behaviour of sea stars Species shown in video is not the Knobbly sea star. The larva of this species are planktotrophic (Scheibling & Metaxas, 2008), feeding on plankton during the larval stage for development and metamorphosis to the juvenile stage (McEdward, 1997).

**Reproduction**  <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">A strategy to increase the success of fertilization may be to migrate to certain water depths. A study by Bos et al (2008) observed that the Knobbly sea star moved away from intertidal habitats during the spawning period to avoid the risk of being excluded from reproduction during low tide. <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">When spawning, female Knobbly sea stars have been observed to be elevated on their ray tips in an arched posture similar to females of Oreaster reticulatus(another sea star in the same family (Scheibling & Metaxas, 2008). . <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">Unlike other sea stars, spawning aggregations have not been observed in P. nodosus. Instead, they are randomly distributed and when experimentlally aggregated by Scheibling & Metaxas (2008), they rapidly returned to pre-manipulation density. This may reflect a compromise between minimizing intraspecific competition for food and maximizing fertilization success.

<span style="font-family: Tahoma,Geneva,sans-serif; font-size: 13px;">**Spawning period:** <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">March to May at full moon (Scheibling & Metaxas, 2008, Bos et al, 2008).

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">**Defense** <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">How do the Knobbly sea star escape predation if they are unable to move fast? <span style="color: #000000; font-family: Tahoma,Geneva,sans-serif; font-size: 13px;">**Physical:** <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">Knobbly sea stars manage this by having massive and ornate cardinal spines as well as a robust and heavily calcified body that serves as defences against any enemy (Scheibling & Metaxas, 2008).

<span style="font-family: Tahoma,Geneva,sans-serif; font-size: 13px;">**Chemical:** <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">They also produce a type of organic chemical known as saponins, found in their body wall, which makes them taste unpleasant and toxic to many predators (Minale et. al, 1982). <span style="color: #000000; font-family: Tahoma,Geneva,sans-serif; font-size: 13px;">back to top ^

=<span style="color: #008000; font-family: Arial,Helvetica,sans-serif; font-size: 24px;">Distribution = <span style="color: #008000; font-family: Arial,Helvetica,sans-serif; font-size: 24px;"> <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">This species has a broad geographic distribution in the western tropical Pacific and Indian Ocean, ranging from the Seychelles to Australia and Japan to southernmost China, and can be found in depths from 1 to 30 m (Clark H.L., 1946, Clark and Rowe, 1971).

<span style="color: #000000; font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">It has been previously recorded as common or abundant in Palau, New Caledonia, the Philippines, and Madagascar (Scheibling & Metaxas, 2008)<span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">. <span style="color: #000000; font-family: Tahoma,Geneva,sans-serif; font-size: 13px;">back to top ^

<span style="color: #008000; font-family: Arial,Helvetica,sans-serif; font-size: 14px;"> **<span style="color: #008000; font-family: Arial,Helvetica,sans-serif; font-size: 24px;">Description ** <span style="font-family: Arial,Helvetica,sans-serif; font-size: 120%;">**Juvenile** <span style="display: block; font-family: Tahoma,Geneva,sans-serif; text-align: left;"><span style="color: #151414; font-family: Tahoma,Geneva,sans-serif; font-size: 13px;">**Similar to adult, but with** <span style="display: block; font-family: Tahoma,Geneva,sans-serif; font-size: 14px; text-align: left;">-mottled colouration <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">-radius of less than 12 cm (Scheibling & Metaxas, 2008). <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">Juveniles attain reproductive maturity at an estimated age of 2 to 3 years (Bos et al, 2008).
 * <span style="color: #008000; font-family: Arial,Helvetica,sans-serif; font-size: 14px;">- How to identify a Knobbly sea star? **

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 120%;">**Adult** <span style="font-family: Arial,Helvetica,sans-serif; font-size: 110%;"> <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;"> **Color:**Various shades ranging from orange, red, brown and beige to bluish-brown ( Ng et al, 2011)<span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">. <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;"> **Tube feet:** Dark red or purple in colour (What are tube feet?) <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;"> **Body:** Robust, heavily calcified body. <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">Large, darkly pigmented nodules (tubercles) on its dorsal surface, with evenly tapering arms. The nodules are scattered irregularly on the central disk, but aligned in a series along the mid-line of each arm (Lane and Vandenspiegel 2003) <span style="color: #333333; font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">. <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">**Size:**Most adults reach a radius of approximately 15 cm (Schoppe, 2000)<span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;"> but some have been observed up to 20 cm in radius (Clark H.L., 1946) <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">. <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">The knobbly sea star are dioecious (have separate sexes), but the males and females cannot be distinguished without dissection. Female gonads are orange/yellow, male gonads are creamy white (Bos et al, 2008). <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;"> The two sexes occur in the ratio 1:1 (Bos et al, 2008).
 * [[image:taxo4254/adult_brown.jpg caption="Brown Knobbly! Photo by: Ria Tan" link="@http://www.wildsingapore.com"]] || [[image:taxo4254/green.jpg caption="Green Knobbly! Photo by: Ria Tan " link="@http://www.wildsingapore.com"]] || [[image:taxo4254/6_arms.jpg caption="Orange Knobbly with six arms! Photo by: Ria Tan " link="@http://www.wildsingapore.com"]] || [[image:blue.jpg caption="Blue Knobbly! Photo by: Ria Tan " link="@http://www.wildsingapore.com"]] ||

<span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">**Each and every Knobbly is DIFFERENT!** <span style="color: #000000; font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">Each individual Knobbly sea star has a unique number and arrangement of knobs on the dorsal surface that can be used to distinguish two sea stars apart. This allows them to be monitored without the use of any invasive method (Chew, 1993) <span style="color: #000000; font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">. Learn more about how to identify and track them here!



<span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">**Is this a Knobbly?** <span style="color: #000000; font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">The Pentaceraster sea star //(Pentaceraster mammilatus)// has also been observed on the shores of Singapore. However, the presence of knobs should not fool you into believing it is a Knobbly sea star. The Knobbly sea star can be distinguished by a single row of knobs on the upperside of the arms unlike the Pentaceraster sea star. Learn more about the Pentaceraster sea star here!

<span style="color: #000000; font-family: Tahoma,Geneva,sans-serif; font-size: 13px;">back to top ^

=<span style="color: #008000; font-family: Arial,Helvetica,sans-serif; font-size: 24px;">Habitat = <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">The Knobbly sea star is commonly encountered in the inner coral reef flats, seagrass beds <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 70%; vertical-align: super;">8] <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">as well as sandy bottoms (Scheibling & Metaxas, 2008)<span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">. In addition, shallow seagrass beds act as a nursery habitat, where the mottled colouration of juveniles may provide camouflage from fish predators (Scheibling & Metaxas, 2008)<span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">. Late stage juveniles then migrate to sand bottoms habitats (Scheibling & Metaxas, 2008).
 * **Coral rubble** || **Seagrass beds** || **Sandy bottoms** ||
 * [[image:coral_rubble.jpg width="249" height="305" caption="Photo by: Ria Tan" link="@http://www.wildsingapore.com"]] || [[image:seagrass.jpg width="401" height="301" caption="Photo by: Ria Tan" link="@http://www.wildsingapore.com"]] || [[image:choc_chip.jpg width="262" height="294" align="left" caption="Photo by: Ria Tan" link="@http://www.wildsingapore.com"]] ||

<span style="color: #000000; font-family: Tahoma,Geneva,sans-serif; font-size: 13px;">back to top ^

<span style="color: #000000; font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">skip to Ecology =<span style="color: #008000; font-family: Arial,Helvetica,sans-serif; font-size: 24px;">Do YOU know? = **<span style="font-family: Arial,Helvetica,sans-serif; font-size: 14px;">-Interesting facts about sea stars in general **

<span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">**#1 Sea star or Starfish? **  <span style="color: #000000; font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">Sea star and starfish actually refer to the same animal. Although they are commonly known as starfishes, they are actually not fishes, which are vertebrates (animals with backbones). Hence, the scientific community prefers to call them sea stars. Sea stars belong to the class Asteroidea, which means star-like animals. <span style="color: #000000; font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">Sea stars have rows of tube feet found in the grooves on their underside, which they control using a water vascular system. Tube feet helps sea stars to latch on to a surface, move slowly across the substrate, and even flip themselves over! <span style="color: #000000; font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">Watch the video below to see how they use their tube feet to get back to an upright position. media type="youtube" key="44iw5FvYb7s" height="283" width="378" align="center"
 * <span style="color: #000000; font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">#2 Sea stars can move too! **

<span style="color: #000000; font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">They are known as eye spots and are found at the tips of each arm. Unlike our eyes, they cannot see details and only contain light sensitive pigments to detect shadows and changes in brightness of light.
 * <span style="color: #000000; font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">#3 Sea stars have eyes too! **

<span style="color: #000000; font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">The cardiac stomach can be everted out of its body to engulf its prey and digest it externally. This stomach is then brought back inside its body, where the partially digested food is moved to the second stomach- the pyloric stomach, for further digestion. Due to its ability to digest food outside it's body, the cardiac stomach allows a sea star to prey on animals larger than its mouth! <span style="color: #000000; font-family: Tahoma,Geneva,sans-serif; font-size: 13px;">back to top ^
 * <span style="color: #000000; font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">#4 Sea stars have two stomachs! **

=<span style="color: #008000; font-family: Arial,Helvetica,sans-serif; font-size: 24px;">Ecology = <span style="font-family: Arial,Helvetica,sans-serif; font-size: 110%;"> **<span style="font-family: Arial,Helvetica,sans-serif; font-size: 120%;">Role in the enviroment ** <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">The Knobbly sea star invests a great portion of its time in feeding and foraging (Scheibling & Metaxas, 2008)<span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">. By continuously reworking surface sediments and digesting living and detrital particulate organic material in sand and seagrass habitats, they may exert an important top-down control on the microbial and meiofaunal communities and thus play an important ecological role in their habitat (Scheibling & Metaxas, 2008)<span style="font-family: Tahoma,Geneva,sans-serif; font-size: 11.2px; vertical-align: super;">. <span style="color: #ffffff; font-family: Tahoma,Geneva,sans-serif; font-size: 11.2px; vertical-align: super;">. <span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 120%;"> **Predators** <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;"> This species was found to be preyed upon by the gastropod //Charonia tritonis// (Thomassin, 1976)<span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">. Fishes such as the pufferfish and triggerfish are also likely predators as fish-bite scars have been observed on the smooth papular areas of their oral surface (Scheibling & Metaxas, 2008, Ng et al, 2011)<span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">. <span style="color: #ffffff; font-family: Tahoma,Geneva,sans-serif; font-size: 11.2px; vertical-align: super;">. <span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 120%;">**Commensalism / Host** <span style="color: #000000; font-family: Tahoma,Geneva,sans-serif; font-size: 14px;"> The Knobbly sea star provides a habitat to a number of commensals, including scale worms, shrimps and crabs and plays host to several parasitic molluscs // ( // Coleman, 2007). <span style="color: #000000; display: block; font-family: Tahoma,Geneva,sans-serif; font-size: 13px; text-align: right;">back to top ^

=<span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 24px; height: 238px; width: 224px;"> <span style="color: #008000; font-family: Arial,Helvetica,sans-serif; font-size: 24px;">Threats to the Knobbly sea star = <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">The Knobbly sea star is extensively harvested as an ornamental decorative for the marine curios trade as well as the aquarium trade.

<span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">In countries where they are abundant, they are frequently encountered in shallow water habitats and are easily collected. They are then left out in the sun to be air dried and sold in souvenir shops. As they are a slow growing species (Bos et al, 2008),<span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;"> such overharvesting may lower fertilization rates of populations such that the species cannot persist locally. <span style="color: #ffffff; font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">**.** <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">The Knobbly sea star is also popular as pets in aquariums. However, these sea stars are hard to keep in captivity and often die after awhile due to stress and starvation. Learn more about it here! <span style="color: #d41111; font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">**Please RECONSIDER if you are thinking of getting one as a pet!**
 * <span style="color: #d41111; font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">The next time you visit such places, DO NOT be tempted to buy them back as souvenirs! **

<span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">The loss or deterioriation of shallow coastal habitat due to human activities may also limit recruitment to populations of Knobbly sea stars (Bos et al, 2008). <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">This is especially so for the seagrass meadows that serve as nursery areas for juveniles. Thousands of Knobbly sea stars harvested from their natural habitat and left out to dry || || <span style="color: #000000; font-family: Tahoma,Geneva,sans-serif; font-size: 13px;">back to top ^
 * [[image:curiostrade.jpg align="left" link="@http://3.bp.blogspot.com/_L3sNLmoKUl4/SJkLw5w0oSI/AAAAAAAABHA/9zIDJEwmWo4/s1600-h/protoreaster-1000s.jpg"]][[image:curiosbasket.jpg align="center" link="@http://3.bp.blogspot.com/_L3sNLmoKUl4/SJkH_bp-D6I/AAAAAAAABGw/yzoTHhc2FVE/s1600-h/protoreaster-dry.jpg"]]

=<span style="font-family: Arial,Helvetica,sans-serif; font-size: 24px;"> The Knobbly sea star in Singapore <span style="font-family: Arial,Helvetica,sans-serif; font-size: 24px;"> =

<span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;"> **National Status**: **Endangered (EN)** under the Singapore Red Data Book 2008. <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">The Knobbly sea star is uncommon in Singapore waters except at isolated locations on reef flats in the Southern Islands (Pulau Semakau, Pulau Sekudu and Cyrene reef) and Chek Jawa (Ng et al, 2011, Davison et al.,2008).<span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">In Singapore, it is vulnerable to potential mutilation or disturbance by reef walkers and to habitat loss during reclamation (Davison et al.,2008)<span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">. The knobbly sea star is also threatened by unusually heavy rainfalls such as the one over southern Johor in December 2006 and January 2007, which led to excessive amounts of freshwater runoff and a drop in salinity that caused a mass mortality of many benthic organisms, including the knobbly sea star (Ng et al, 2011)<span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">. <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">Watch this video to see a Knobbly sea star in the seagrass beds of Cyrene reef! <span style="font-family: Arial,Helvetica,sans-serif; font-size: 110%;"> media type="custom" key="11219704" <span style="color: #000000; font-family: Tahoma,Geneva,sans-serif; font-size: 13px;">back to top ^

=<span style="color: #008000; font-family: Arial,Helvetica,sans-serif; font-size: 24px;">Taxonavigation = <span style="color: #008000; font-family: Tahoma,Geneva,sans-serif; font-size: 13px;"> -This allows identification of biological groupings of the sea star <span style="color: #000000; font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">**Kingdom:** Animalia <span style="color: #000000; font-family: Tahoma,Geneva,sans-serif; font-size: 14px;"> **Phylum:** Echinodermata <span style="color: #000000; font-family: Tahoma,Geneva,sans-serif; font-size: 14px;"> **Class:** Asteroidea <span style="color: #000000; font-family: Tahoma,Geneva,sans-serif; font-size: 14px;"> **Order:** Valvatida <span style="color: #000000; font-family: Tahoma,Geneva,sans-serif; font-size: 14px;"> **Family:** Oreasteridae <span style="color: #000000; font-family: Tahoma,Geneva,sans-serif; font-size: 14px;"> **Genus:** //Protoreaster// <span style="color: #000000; display: block; font-family: Tahoma,Geneva,sans-serif; font-size: 13px; text-align: right;">back to top ^

=<span style="color: #008000; font-family: Arial,Helvetica,sans-serif; font-size: 24px;"> Taxonomic history = <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;"> // Protoreaster nodosus // is an accepted name (WoRMS) <span style="color: #000000; font-family: Tahoma,Geneva,sans-serif; font-size: 14px;"> Earliest name of the species as designated by Linnaeus in the 10th edition of Systema Naturae: //Asterias nodosa// (Linnaeus, 1758) <span style="color: #ffffff; font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">. <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 110%;">**Etymology** <span style="color: #008000; font-family: Tahoma,Geneva,sans-serif;">- What is the origin of the name? <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;"> The species epithet // nodosus, // refers the nodules found on the dorsal surface of the sea star. <span style="color: #ffffff; font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">. <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">**Synonymised taxa** <span style="color: #008000; font-family: Arial,Helvetica,sans-serif;">- In taxonomy, a synonym is a scientific name that arises when the same taxa is named more than once independently or during a change in exisiting taxa (e.g. when two genera are merged to become one). Only ONE scientific name is considered to be the correct one at any one time. The other inappropriate ones become the synonyms of the same species.

<span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">Oreaster nodosus Bell, 1884. (One of the more commonly used synonym in past literature) <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;"> Other synonymised taxa can be found here. <span style="color: #000000; font-family: Tahoma,Geneva,sans-serif; font-size: 13px;">back to top ^

=<span style="color: #008000; font-family: Arial,Helvetica,sans-serif; font-size: 24px;"> Type Information = <span style="color: #008000; font-family: Arial,Helvetica,sans-serif; font-size: 13px;"> - A type is one particular specimen or a group of specimens of an organism to which the scientific name is formally attached to. It should have all or most of its diagnosable characters and may be referred upon if there are any uncertainties, such as when revising the genus or species name or determining if another new species is found. <span style="color: #ffffff; font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">. <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;"> Status and whereabouts for the holotype of // Asterias nodosa // (Linnaeus, 1758) remains undetermined. <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;"> Other specimens can be found at the Raffles Museum of Biodiversity Research in Singapore, Museum Victoria and Smithsonian Natural Museum of Natural History <span style="color: #000000; font-family: Tahoma,Geneva,sans-serif; font-size: 13px;">back to top ^

=<span style="color: #008000; font-family: Arial,Helvetica,sans-serif; font-size: 24px;">Diagnosis = <span style="color: #008000; font-family: Arial,Helvetica,sans-serif; font-size: 14px;">- A diagnosis helps to correctly identify one species from another <span style="color: #ffffff; font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">. <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">//Protoreaster nodosus// can be differentiated from P. nodulosus by it size. The radius of full grown //P. nodulosus//does not exceed 16cm whereas full grown //P. nodosus// have a radius of up to 20cm (Clark H.L., 1946) <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 14px;">. The absence of red in the colouration of //P. nodulosus//is another conspicuous difference between the two species (Clark H.L., 1946). <span style="color: #000000; font-family: Tahoma,Geneva,sans-serif; font-size: 13px;">back to top ^

=<span style="color: #008000; font-family: Arial,Helvetica,sans-serif; font-size: 24px;">Links to other webpages = <span style="color: #008000; font-family: Arial,Helvetica,sans-serif; font-size: 12px;"> **[|Wild Singapore]** <span style="color: #008000; font-family: Arial,Helvetica,sans-serif; font-size: 12px;"> **[|World Register of Marine Speces]** Encyclopedia of Life [|Project Semakau] Wikipedia GenBank <span style="color: #000000; font-family: Tahoma,Geneva,sans-serif; font-size: 13px;">back to top ^
 * <span style="color: #008000; font-family: Arial,Helvetica,sans-serif; font-size: 14px;">- Find out more information regarding the Knobbly sea star, //Protoreaster nodosus//. **

<span style="color: #008000; font-family: Arial,Helvetica,sans-serif; font-size: 24px;">**Literature and References** <span style="color: #000000; font-family: Tahoma,Geneva,sans-serif; font-size: 14px;"> Scheibling, R. E., and Metaxas,A.,(2008) Abundance, Spatial Distribution, and Size Structure of the Sea Star Protoreaster nodosus in Palau, with Notes on Feeding and Reproduction. Bulletin Of Marine Science, 82(2): 221–235.

Bos, A. R., Gumanao ,G. S., Alipoyo, J. C. E., Cardona,L.T. (2008). Population dynamics, reproduction and growth of the Indo-Pacific horned sea star, Protoreaster nodosus (Echinodermata; Asteroidea).__Marine Biology__ **156**(1): 55-63.

Ng, P. K. L., Corlett R. T., Tan, H. T. W. (2011). Singapore Biodiversity: An Encyclopedia of the Natural Environment, Natl Book Network.

Lane, D. J. W. and Vandenspiegel, D., (2003). A guide to sea stars and other echinoderms of Singapore. Singapore Science Centre, p. 64-65.

Schoppe, S. (2000). A guide to the common shallow water sea stars, brittle stars, sea urchins, sea cucumbers and feather stars (Echinoderms) of the Philippines. VISCA-GTZ Applied Tropical Ecology Program, Visayas State College of Agriculture, Baybay, Leyte, Philippines and Times Editions Singapore, 144 p.

Clark, H.L., (1946). The Echinoderm Fauna Of Australia, its composition and its origin. Carnegie Institution of Washington. Publication 566. Pp105-106.

Chew, T. C., (1993). Individual recognition and digestive anatomy of //Protoreaster nodosus// (L. 1758) (Echinodermata: Asteriodea). BSc Honors thesis, National University of Singapore.

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McEdward, L. R. (1997). Reproductive Strategies of Marine Benthic Invertebrates Revisited- Facultative Feeding by Planktotrophic Larvae. __The American Naturalist__ **150**(1): 48-72

Coleman, N., (2007). Sea stars: echinoderms of the Asia/Indo-Pacific. Neville Coleman's Underwater Geographic Pty Ltd.

Davison, G. W. H., Ng, P. K. L., & Ho, H. C. (Eds.). (2008). The Singapore red data book: Threatened plants & animals of Singapore. Singapore: Nature Society (Singapore).

Clark AM, Rowe (1971) Monograph of shallow-water Indo-West Pacific echinoderms. No. 690. British Museum (Nat. Hist.), London

L. Minale, C. Pizza, R. Riccio And F. Zollo, (1982). Steroidal Glycosides From Starfishes Pure & Appl.Chem. ,J., Vol.54, No.10, Pp.L935—I950. <span style="color: #000000; font-family: Tahoma,Geneva,sans-serif; font-size: 13px;">back to top ^

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