Acontia: Thin white or colored threads attached at one end to the borders of the mesenteries, as a rule proximal to the filaments, the other end is free. They are laden with extraordinarily numerous nematocysts of various categories (Carlgren, 1949: p.7). They can be protruded through the mouth, and in some cases through special pores (cinclides) in the body-wall, for purposes of defense or paralyses of prey. In histological structure they differ completely from the mesenterial filaments.

 

Acontia Images: (species names are linked to the Hexacorallian database)

Species Andvakia Mirabilis

CAPTION
Fig. 7. Do., Acontia with its nematocyst battery, magnified.

Species Phellia margaritacea

CAPTION
Fig. 8. *Phellia margaritacea*; Acontia, greatly magnified.

Species Edwardsia andresi

CAPTION
Fig. 10. An acontia greatly magnified

Species Sagartia schilleriana

CAPTION
Fig. 8. Longitudinal section of a portion of a craspedum, and 8 a, its cnidæ, more enlarged (p. 43)

Species Sagartia schilleriana

CAPTION
Fig. 9. Longitudinal section of a portion of an acontium; 9 a and 9 b, its cnidæ (p. 44).

Species Thoe albens

CAPTION
Fig. 8. *Thoe albida*. Portion of an acontium. (From a rough slide-diagrammatic.) The nerve-cells appear to be on one side, the nematocysts on the other.

Species Kodioides pedunculata

CAPTION
Fig. 10. an acontia, magnified.

Species Chondrodactis japonica

CAPTION
*Chondrodactis japonica* Figur 95. Acontien. Imm. 1,5 Oc. 2.
     

Species Chondrodactis magna

CAPTION
*Chondrodactis magna* Figur 91. Acontien. Imm. 1,5 Oc. 2.

      
CROSS SECTIONS:
 

Species Actinothoe glandulosa

CAPTION
Fig. 13. Reprinted with permission of the Royal Swedish Academy of Sciences.

Species Nemanthus californicus

CAPTION
Text-figure 3. *Nemanthus californicus*. Transverse sections of an acontium-like thread.

Species Calliactis androgyna

CAPTION
i) Querschnitt eines Acontiums mit Flosse und lichtbrechenden Drüsenzellen (Drü)."" Reprinted with permission of the author.
 
 

Species Pelocoetes minima

CAPTION
*Pelocoetes minima*. Transverse section through an acontium. gl.c., gland-cell; m., mesoglea; mu., mucus-cell; n., nematocysts. X 600.

 

Species Sagartia Lactea

CAPTION
Fig. 75. Transverse section of acontium of *S. lactea.* Zeiss D 2.

Species Artemidactis victrix

CAPTION
Fig. 3.-*Artemidactis victrix*. Diagram showing shape and layering of transverse section of acontium. Oc. 3, obj. 1/6.