Resumen de Staining protocol for the histological study of sea anemones (Anthozoa: Actiniaria) with recommendations for anesthesia and fixation of specimens
- español
Many of the characters used in the sea anemone taxonomy can only be examined through histological sections. Since there is not a standardized procedure for this purpose, various anesthesia and fixation techniques are discussed on the intertidal species Anthopleura hermaphroditica and Bunodactis hermaphroditica. Using the Masson’s trichrome method, further modifications are proposed to the staining protocol according to the results obtained on this species. The combined effects of menthol crystals in short spans along with small doses of MgCl2 were the most satisfactory anesthetic for keeping the organisms in expanded position. The best preparations were obtained from samples fixed for long periods in 8% seawater formalin; however, in order to achieve a good differentiation of the tissue, mordanting the samples with Bouin’s fixative was necessary. Besides being a fast method, the modified Masson’s trichrome gives very good contrasts between the epithelia and the mesoglea, allowing to control the timing of differentiation along the staining. Doing both suggestions as precautions, this paper offers a practical help for the study of the histology of sea anemones.
- English
Many of the characteristics used in sea anemone taxonomy can only be examined through histological sections. Since there is no standardized procedure for this purpose, various anesthesia and fixation techniques applied to specimens of the intertidal species Anthopleura hermaphroditica and Bunodactis hermafroditica are discussed. Additionally, further modifications are proposed to the Masson’s trichrome method according to the results obtained on these species. The combined effect of the short application of menthol crystals, together with small doses of MgCl2 were the most satisfactory anesthetics for maintaining the specimens expanded. The best preparations were obtained from samples fixed for several months in 8% seawater formalin; however, in order to achieve a good differentiation of the tissue, mordanting the samples with Bouin’s fixative was necessary. Besides being a fast method, the modified Masson’s trichrome gives very good contrasts between the epithelia and the mesoglea, and allows controlling the timing of differentiation during staining. The present paper includes suggestions and precautions and thus offers practical help for the histological study of sea anemones.
