Sea apple is the common name for the colorful and somewhat round sea cucumbers of the genusPseudocolochirus, found in Indo-Pacific waters.[2][3] Sea apples are filter feeders with tentacles, ovate bodies, and tube-like feet. As with many other holothurians, they can release their internal organs or a toxin into the water when stressed.[3][4]
Sea apples are holothuroids, and as such share many of the same physical characteristics. A few notable characteristics are discussed below.
Anatomy and feedingedit
The ovate body of an adult sea apple can grow up to 7.8 inches (20 cm) long.[5] A central mouth-like cavity is surrounded by feathery tentacles, which add additional length.[4] Sea apples, like many echinoderms, have rows of tube feet which help them move over and adhere to structures.[4]
The bodies and tentacles of sea apples come in many different colorings. The Australian species has a primarily purple body, red feet, and purple and white tentacles.[4]
The sea apple feeds primarily on plankton, which it filters from the water with its tentacles.[4] It alternately brings each tentacle to its mouth, scraping off the captured plankton.[3]
Sea apples usually feed at night, a time when their delicate tentacles are less at risk from predators.[3]
Defenseedit
When disturbed, sea apples, like other holothuroids, can violently extrude their entrails from both ends.[6] In addition, sea apples can release a toxic saponin called holothurin into the water as a defense mechanism.[5]
In addition, if threatened or in an unsuitable environment, sea apples can consume large amounts of surrounding seawater to swell to nearly double their original size, this allows them to be moved to a new area by water currents, and much more quickly than they could walk.[7]
Because of their interesting appearance and behaviour, sea apples are often widely desired as specimen for display marine aquaria. They are considered reef safe as far as their compatibility with other species.[5] However, they can be considered unsafe for reef aquaria for multiple reasons:
Starvationedit
Sea apples often starve to death in display aquaria.[4] Levels of plankton in aquaria are often lower than optimal, and sea apples are often seen attempting to feed not only at night, as in their natural habitat, but also in the daytime.[3] With only low levels of food available, these sea apples often starve, becoming progressively smaller as this happens.[4] To try to circumvent these problems, hobbyists attempt to give the sea apple specimens supplemental feedings of plankton and liquid food.[3][7]
Harassment and predationedit
Sea apples are often harassed by many aquarium inhabitants. Crustaceans, such as hermit crabs, and fish often peck or pick at sea apple's feathery tentacles.[4][7] This may be for predatory purposes, or simply to steal trapped particles and plankton from the tentacles.[7]
Occasionally, sea apples use their defense mechanisms in response to harassment. The release of their toxin can poison other aquarium inhabitants,[5][7] and is one of the reasons they are not commonly seen in aquariums.[8]
apple, tropical, tree, syzygium, grande, common, name, colorful, somewhat, round, cucumbers, genus, pseudocolochirus, found, indo, pacific, waters, filter, feeders, with, tentacles, ovate, bodies, tube, like, feet, with, many, other, holothurians, they, releas. For the tropical tree see Syzygium grande Sea apple is the common name for the colorful and somewhat round sea cucumbers of the genus Pseudocolochirus found in Indo Pacific waters 2 3 Sea apples are filter feeders with tentacles ovate bodies and tube like feet As with many other holothurians they can release their internal organs or a toxin into the water when stressed 3 4 Sea apple Pseudocolochirus violaceus Scientific classification Domain Eukaryota Kingdom Animalia Phylum Echinodermata Class Holothuroidea Order Dendrochirotida Family Cucumariidae Genus PseudocolochirusPearson 1910 Species 1 Pseudocolochirus axiologus H L Clark 1914 Pseudocolochirus misakiensis Yamana amp Kohtsuka 2018 Pseudocolochirus unica Cherbonnier 1988 Pseudocolochirus violaceus Theel 1886 Synonyms 1 Koehleria Cherbonnier 1988 Contents 1 Physiology 1 1 Anatomy and feeding 1 2 Defense 2 Problems in captivity 2 1 Starvation 2 2 Harassment and predation 3 References 4 External linksPhysiology editSee also Sea cucumber Anatomy nbsp Sea apple at Nusa Kode nbsp Pseudocolochirus violaceus amongst other invertebrates Sea apples are holothuroids and as such share many of the same physical characteristics A few notable characteristics are discussed below Anatomy and feeding edit The ovate body of an adult sea apple can grow up to 7 8 inches 20 cm long 5 A central mouth like cavity is surrounded by feathery tentacles which add additional length 4 Sea apples like many echinoderms have rows of tube feet which help them move over and adhere to structures 4 The bodies and tentacles of sea apples come in many different colorings The Australian species has a primarily purple body red feet and purple and white tentacles 4 The sea apple feeds primarily on plankton which it filters from the water with its tentacles 4 It alternately brings each tentacle to its mouth scraping off the captured plankton 3 Sea apples usually feed at night a time when their delicate tentacles are less at risk from predators 3 Defense edit When disturbed sea apples like other holothuroids can violently extrude their entrails from both ends 6 In addition sea apples can release a toxic saponin called holothurin into the water as a defense mechanism 5 In addition if threatened or in an unsuitable environment sea apples can consume large amounts of surrounding seawater to swell to nearly double their original size this allows them to be moved to a new area by water currents and much more quickly than they could walk 7 Problems in captivity edit nbsp Pseudocolochirus violaceus Because of their interesting appearance and behaviour sea apples are often widely desired as specimen for display marine aquaria They are considered reef safe as far as their compatibility with other species 5 However they can be considered unsafe for reef aquaria for multiple reasons Starvation edit Sea apples often starve to death in display aquaria 4 Levels of plankton in aquaria are often lower than optimal and sea apples are often seen attempting to feed not only at night as in their natural habitat but also in the daytime 3 With only low levels of food available these sea apples often starve becoming progressively smaller as this happens 4 To try to circumvent these problems hobbyists attempt to give the sea apple specimens supplemental feedings of plankton and liquid food 3 7 Harassment and predation edit Sea apples are often harassed by many aquarium inhabitants Crustaceans such as hermit crabs and fish often peck or pick at sea apple s feathery tentacles 4 7 This may be for predatory purposes or simply to steal trapped particles and plankton from the tentacles 7 Occasionally sea apples use their defense mechanisms in response to harassment The release of their toxin can poison other aquarium inhabitants 5 7 and is one of the reasons they are not commonly seen in aquariums 8 References edit a b WoRMS 2009 Pseudocolochirus Pearson 1910 World Register of Marine Species Retrieved March 8 2010 Sea apple sea cucumber Pseudocolochirus violaceaus on Chek Jawa Pulau Ubin Singapore Wildsingapore homepage 2003 lt http www wildsingapore com chekjawa text c624 htm gt a b c d e f Stratton Richard Mini Reef Aquariums Yearbook Neptune NJ T F H Publications ISBN 0 7938 1976 8 a b c d e f g h Haywood Martyn Sue Wells 1989 The Manual of Marine Invertebrates Morris Plains NJ Tetra Press Salamander Books Ltd p 208 ISBN 3 89356 033 5 a b c d Nilsen Alf Jacob Svein A Fossa 2002 Reef Secrets Neptune City NJ T F H Publications ISBN 978 1 890087 67 8 Goldstein Robert J 1997 Marine Reef Aquarium Handbook Hauppauge NY Barron s Educational Series Incorporated ISBN 0 8120 9598 7 a b c d e Lougher Tristan 2007 What Invertebrates A Buyer s Guide for Marine Aquariums Hauppauge NY Barron s Educational Series Incorporated ISBN 978 0 7641 3741 9 Saltwater Invertebrates for Marine Reef Aquariums Sea Apple Aquarium Fish Tropical Freshwater Fish and Saltwater Fish for Home Aquariums 2008 lt http www liveaquaria com product prod display cfm c 497 502 711 amp pcatid 711 gt External links editPhotos of Sea apple on Sealife Collection Retrieved from https en wikipedia org w index php title Sea apple amp oldid 1196757314, wikipedia, wiki, book, books, library,
