Microscopic observation of tentacles' cross-section

Thank you very much for the useful comment.

When you get subtidal or intertidal sea anemone the methodology to employed is the same.

You must look :1.the external aspect of column (body) and see there is  vesicles,verrucae,acrorhagi or pseudoacrorhagi,cinclides,tenaculli,nematybome or these structure are absent so the column  is smooth.2,you must see the tentacles and how many cycles of tentacles there are.,and they are counting from the mouth to the margin (upper zone of the column )The cycles of tentacles  corresponding to first cycle nearest to mouth,corresponding to second cycle is  following, corresponding to third cycle is following and so.Generally there are three to six cycles no more.2.the internal anatomy ,so you must do two ways:a. histology cross sectión for looking mesenteries and the sphincter and sterile or fertil mesentery (=gonads).You must see how many fertil mesenteries there are and you must do to contain the number of mesenteries too and the cycles of them.The cycles of mesnteries are the first cycle,the second cycle,and so on.The first cycle go from the column  to throat ,the second cycle go from column to middle way of the first cycle,the third cycle go from column to middle ways to the second and so on.b.cros section on half of sea anemone and put it under water and look it with stereo microscopic.This way is only usefull when the researcher is an expertise,any way I don´t recomend the way b,because it is possible lost to much informations. .When you study mesenteries,you too see the mesenterial filaments;it is to the end of mesentery.You must know the directive mesentery (DM);generally there are two DM and these cross the sea anemone in two same half.In histology cross section the DM can see with retractor muscle face to face.The retractor muscle is a muscle located at half of mesentery and the others mesenteries haven the retractor muscle in front face to face. 

3.The study of cnidocysts:You must look the differents types of cnidocysts;these are in the tentacles,column,throat ,mesenteries,acrorhagi or pseudoacrorhagi and mesenterial filaments.The cnidocyst are the differents kinds and you to get the meassure of each one.

I hope all writted here to be usefull for you and for you study.

 You must look the following references:

Carlgren,O.1940.A contribution to the knowledge of the structure and distribution of the cnidae in Anthozoa.Lunds Univ.Arsskr.N.F.,36;1-62.

Fautin,D.G. and R.N.Mariscal.1991.Cnidaria:Anthozoa.In:Microscopic Anatomy of Invertebrates.Vol.2:Placazoa,Porifera,Cnidaria and  Ctenophora.pp.267-358.Wiley Liss.

Schmidt,H.1969.Die Nesaselkapsel der Aktinien und ihre differential diagnostische.Bedenutung.Helgoländer wiss.Meeresunter.,Hamburg,19(2):284-313.

And more actualiy the web site: Hexacorallians of the world.

Dear Mauricio,

Thank you so much for the useful comments.

Regards

Hy, Moslem

The best (and more complete) key for sea anemones identification is, undoubtedly, that of Carlgren 1949:

CARLGREN, O. 1949. A survey of the Ptychodactiaria, Corallimorpharia and Actiniaria. Kungliga Svenska Vetenskapsakademiens Handlingar, Fjärd Serien Band 1 (1): 1-121

To understand and recognize the structures you need to identify in the material, please consult:

STEPHENSON, T.A. 1928. The British Sea Anemones. Ray. Soc. v. I n.113 (1927), p. 1-148, figs 1-41 t. 1-14

Concerning methodology, when you collect the anemones you have first to anesthetizate them in a small bowl with sea water, using either a small amount of menthol crystals on the surface of the water or slowly drip a solution of magnesium chloride (or sulfate) and wait until the specimen gets anesthetizated (when it doesn't contract the tentacles anymore). This procedure causes the tentacles to keep exposed and the tissues and other structures, in general, don't look contracted! Then, fix the specimens in a 10% saline formaldehyde solution, better prepared using sea water of the same area. Finally, you have to prepare the material to obtain histological sections, stain these sections with Hematoxilyn and Eosin and/or using a trichromic dye (like Mallory's or Gomori's). All these methodologies can be obtained in a good book of Histological Techniques.

Good luck, Moslem. When you get your slides prepared post me a photo, please!

Best wishes,

Priscila.