«Description a Sea Cucumber Species Holothuria atra Jaeger, 1833 from Kish Island Iran (Echinodermata: Holothuroidea) Akram Tehranifard, M.R. ...»
J. Basic. Appl. Sci. Res., 2(12)12660-12664, 2012
Journal of Basic and Applied
© 2012, TextRoad Publication
Description a Sea Cucumber Species Holothuria atra Jaeger, 1833 from
Kish Island Iran (Echinodermata: Holothuroidea)
Akram Tehranifard, M.R. Rahimibashar
Department of Marine Biology, Lahijan branch.Islamic Azad University Lahijan, Iran
ABSTRACTAs each new species evolved, the ossicles changed with it, so each species has uniquely shaped ossicles.
Examination of gross morphology and microscopic ossicles showed that this species is Holothoria atra.
Color uniformly black or dark brown; when alive body usually covered with sand coating of sand which may also serve to keep it cool by protecting it from the sun's rays., except for several pairs bare patches dorsally; tables with reduced but sometimes spinose disc. The importance of detailed reproductive biological studies on Holothuria atra are necessary due to its important role in the conservation of the marine environment. This species found on subtidal sand and grassbed, 3to 4 m depth at Kish Island. Distributed throughout most of the tropical Indo-Pacific area. Holothoria atra, is a holothurian of order Aspidochirotes belonging to the family Holothuriidae genus Holothuria. It is deposit-feeder and is mainly found on sandy bottom of fringing reefs surrounding the Kish island. Holothoria atra, is a holothurian of order Aspidochirotes belonging to the family Holothuriidae genus Holothuria. Holothuria atra is an omnivore, sifting through the sediment with its tentacles and feeding on detritus and other organic matter. It ingests sand at the same time and digests the biofilm on the sand grains before ejecting them through its anus.
KEYWORDS:Holothurians – Echinoderms – Holothuriidae– Holothuria – Kish island – Persian Gulf
INTRODUCTIONSea cucumbers are members of the class Holothuroidea within the invertebrate phylum Echinodermata (which literally means "spiny skins"). Sea cucumbers (Holothuroidea) inhabit sheltered shallow-water sediments in all tropical and temperate oceans, but their greatest abundance and diversity occur in the tropical Indo-Pacific region (Conand, 1993).
Holothurians are very important members of benthic communities as they can cause significant changes in the sea floor sediment composition. Sea cucumbers are the most commonly consumed echinoderms and have been eaten since ancient times. The original idea for FAO publication is a simple identification guide for commercial sea cucumber species information.
The study area covered Kish island lies between 53 , 5 3 to 54 , 4 E and 26 , 2 9 and 26 , 3 5 N. This island has an area of 90 square kilometers and is 18 km away from the southern mainland of the Iran. It is a coral island with fringing reefs. This island is one of the most important recreational sea side along the coast and also as a free Trade Zone, imposing lots of pressure on the marine environment resulting in the destruction and disappearance of corals and coral communities in the last 10 years. This also the place where most of the sampling was done, for 16 months by local diverse using the scuba diving apparatus.
Altogether, 160 specimen were collected at all depths around the island but mainly from the east coast. We measured wet weight and contracted lenghth, respectively. Lenghth measured from the mouth to the anal pore. The procedure for obtaining spicules is very simple. A slice (1cm2 ×1 mm thickness) is cut from the dorsal area then placed in a small test tube with 3 ml of commercial bleach. After 10-20 minutes transferred the fine white sediment onto a microscope slide by using a pipette. The covered slip, and examine using a microscope with 100x magnification.
Corresponding Author: Akram Tehranifard, Depatment of Marine Biology, Lahijan branch. Islamic Azad University Lahijan, Iran. E-mail: Akram.Tehranifard95@gmail.com
Holothuria atra weights varied between 50 gr and 500gr.The highest weight was in April, while the lowest weight was recorded in Febuary. The shape of this sea cucumber is an elongate cyclinder from 90mm but known to grow up to 600mm.
1. Overall shape: It is approximately cylindrical in shape but with a more or less flattened ventral sole. (Figure1).
2. Maximum body length: Length exceptionally up to 600 mm or more,but usually up to 300 mm.
3. Body wall: soft but fairly thick.
4. Position of mouth:Mouth is ventral.
5. Position of anus: The anus is approximately terminal.
6. Pharyngeal introvert: It is a retractile portion of the anterior body wall that allows the complete retraction of the tentacle. This character is not found in this species.
7. Ossicles: ossicles are fairly numerous consisting of tables and rosettes in various stages of development.
8. Tentacle shape: Tentacles are fairy long and leaf-shaped.
9. Tube feet: Podia consisting of numerous pedices crowded on the ventral surface.
10. Rete mirabile: In the family of Holothuriidae has extensive rete mirabile.
11. pedicels: pedicels are numerous and crowded on the ventral side.
12. Respiratory tree: The right respiratory tree extends forward to the calcareous ring and is firmly attached to the body wall and the left one is shorter.
13. Cuvierian organ: It hasn’t cuvierian organ.
14. Gonads: Gonads are single, consisting of numerous filamentous tubules united basely into one tuft attached to the left side of the dorsal mesentrery and hang freely in the coelom.
15. Cloacal musles: Cloacal muscles adjoin the posterior body wall and the cloaca. They are well developed.
16. Feeding: This species is an omnivore, sifting through the sediment with its tentacles and feeding on detritus and other organic matter.
17. Habitat and Depth Range: Subtidal sand and grassbed; 3-4 m depth.
18. Collection Site: Kish Island
19. General Distribution: Throughout most of the tropical Indo-acific area.
It is well-known that ossicles are the main taxonomic character in holothuroids (Thandar, 1987a).
Ossicles are crystals of calcium carbonate and are a unique anatomical body features of sea cucumbers used specifically for the identification purposes.The ossicles were measured on a transect across a slide prepared from the mid–dorsal region of each specimen. Also, for the correct identification some specimen has been sent to Prof, David Pawson at the National Museum of Natural history, Washington DC, United States.
Holothuria (Halodeima) atra Jeager Holothuria (Halodeima) atra jaeger ; 1833.22.
Holothuria (Halodeima) atra : Pearson, 1914: 170-171; Bakus, 1968: :23-31; Rowe,1969:137-138.fig7;
Clark & Rowe, 1971:176, pl.27, fig. 11; Rowe & Doty, 1977 : 224,230-231,figs 3d and 7a. Holothuria (Halodeima) atra : Panning.1935 :30-31,fig.22. Holothuria (Halodeima) atra : Semper, 1868: 88, pl. 26;
Heding. 1940:120; Panning. 1944:61-62, fig.29; Cherobinner,1955:141.
Description: A Larg-sizeed Speies of Holothuria, body stout, approximately cylindrical in shope but with a more or less flattened ventral sole; boy wall sofr but fairly thick; muth ventral; anus approximately central;
tentacleetwenty in number, fairly long and leaf-shaped; podia consisting of numerous pedicels crowded on the ventral serface, but more or less confined to the three ambulacra, and fewer smaller papillae scattered over the dorsal surface; colour of live specimens uniformly black or dark brown which is retained after preservation in alcohol; calcareous ring fairly stout, with radial plares up to c. three times the length of the interradials ; spicules fairly numerous, consisting of tables having reduced but sometimes spinose disc and a spire of moderate hight crowned with spineletrs of ming a maltese cross when viewed from above, and rosettes in various stages of development.
Taxonomic Notes :The description of this species was based primarily on BM(NH) material and on occounts in the literature, since specimens were lost from the collections after only tentative identifications had been made (see also PRiCem 191:9). Further Collections From the Gulf are clearly needed.
Distinctive Features : Distinguished from H.(Halodeima) edulis by the uniformly black or dark brown body colouration. and by the disc of the tables which are slightly more developed than those of the latter
12661 J. Basic. Appl. Sci. Res., 2(12)12660-12664, 2012
species. H.(Halodeima) atra is also similar in uniformly dark colour to H.(Mertensiotburnia) leucospilota, but can be distinguished by the spinelets crowing the table spires, wich from the a maltese cross, rather than a small cluster in H.(Mertensiotburia) leucospilata. In the latter species buttons are also present among the spicules, whereas in H.(Halodeima) are buttonos are laking H.( Mertensiotburnia) leucospilota also has the habit in life of stretching out in a thin shake-likefrom.
Key for the shallow water orders of class Holothuroidea:
1a. Podia absent; body vermiform; body wall thin, often translate; dominant spiculess in form of anchors with associated with anchor plates tentacles pinnate; pharynx without retractor muscle; no respiratory tree …………..……….. Apodia.
1b. Podia presents; body wall moderately thick; body wall with dominant spicules in form, of tables, perforated plates, buttons, rods, or rosettes ……….………….. 2.
2a. Tentacles peltate or pelyo – digitate; anterior end of body not introverted and associated with retractor muscles …………… Aspidochirotida (The only order with commercial species in the area).
2b. Tentacles branched anterior end of body introverted, associated with retractor muscles ………………….….. Dendrochirotida.
ID Key for the shallow–water families of Aspidochirotida occurring in the area:
1a. Body with trivium (sole) usually flattened and dorsal bivium convex; gonads forming a single tuft appended to the left dorsal mesentery; cnvierian organs present or absent; dominant spicles of form tables, buttons (simple or modified), and rods (excluding c – and s – shaped rods) ……………………..
Body usually cylindarical in cross section(flattened in Holothoria rigida,but often with a more or less flattened ventral sole; colours various, if the podia are a contrasting colour(Holothuria billa) they are light not dark; spicules divers, but C-shape spicules(rods and military) not present……..Holothuriidae
ID Key for the shallow –water genus of Holothuriidae:
Body wall not smooth or parchment-like; colour of live preserved specimens variable,but not as above;
spicules numerous and diverse,consisting of tables, buttoms,fenestrated spheres and rosettes in various combinations………………..Holothuria Colour uniformly black or dark brown; body usually covered with sand, except for several pairs of bare patches dorsally; tables with reduced but sometimes spinose disc……………Holothuria atra Jaeger,1833
Diagnosis of Genus Holothuria Linnaeus,1767:
Tentacles 17-30, usually 20, papillae and pedicels arranged variously on the dorsal and ventral sides respectively; anal papillae variously developed or absent; body wall 2-20 mm in thickness; body form variously developed, vermiform, cylindrical or with the ventral side distinctly flattened and sole-like dorsally arched; size ranging from small to large even up to 600 mm in length; calcareous ring more or less well developed usually with radial plates two or three times as long as interradial plates.Spicules very diverse and variously developed tables present or absent, rosettes and small branched rods sometimes present.
Identify species:The careful examination of all 160 specimen of sea cucumbers taken from the sea bottom of Kish Island and also taking into account the identification keys used for this purpose, shows spicules rosette present,discs of tables small; colour uniformly dark brown or black…………H,(Halodema atra,Jaeger,1833).
Kingdom: Animalia Phylum: Echinodermata Class: Holothuroidea Order: Aspidochirotida Family:
Holothuriidae Genus: Holothuria Species Holothuria atra Jaeger,1833
Being soft-bodies, holothrian tend to lose their obvious external characteristics quickly, especially on hanling or after death. This feature makes them among the more difficult of marine groups to identify.
Precise taxonomic classification relies greatly on the form of the endoskeleton, which is reduced and which is made of microscopic calcareous spicules, that can adopt a variety of forms, in the skin(Garry L.Preston,1992). Superficial identification of the most common commercial sea cucumbers,at least to genus level, and often further, is nevertheless normally possible based on external visual appearance. The
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Stichopodidae, which contains only two genera (Stichopus and Thelenota) are easy to recognize because of the somewhat square cross-section of the body. The Holothuriidae are divided into four genera, of which two (Actinopyga and Holothuria) are commercially important. Actinopyga genera are easy to recognize because of the presence of five five calcified papillae,or ‘teeth” around anus. Most commercial species of Holothuria are fairly easy to distinguish, but the genus is subdivided into at least 13 varieties and 114 species(Row,1969) which also contain numerous non-commercial types. Among coastal species, the aspidochirotid holothurians, which contain the commercial species, tend to predominate seas(Conand,1986).