OCTOCORALS --- PRESERVATION AND IDENTIFICATION

Virgularia cf. gustaviana (Northern Mindoro, Philippines)

Preservaton Techniques: Never use formalin to preserve octocoral material as the fluid tends to become acidic over time or if it is not buffered properly, and can erode the fine ornamentation of sclerites or even dissolve whole sclerites. In addition, formalin makes tissue material unusable for molecular analysis. Octocorals can be relaxed in a bowl of seawater with a few 7-8% maagnesium chloride solution gradually added. The initial fixative and final preservative should be 75-95% ethanol. For molecular analysis, 95% ethanol is best. For dry-preserved specimens, gorgonians can be sun-dried after washing in fresh water.

Identification of Octocorals: Identifiying octocoral material can often be difficult, problematic, at the least challenging, sometimes ending with an uncertain or tentative conclusion, or downright impossible under given circumstances. Important variables include the level of identication sought - such as an idientification to the genus only or to the species as well. Positive species level identifications are often not be possible, since a taxonomic revision of the relevant genus needs to be accomplished first before species can be known for certain. In addition, type specimens for comparative purposes be have been lost or or damaged or are not designated. The original species description may be extremely brief and uninformative, or lacking in clarity, or not well-illustrated. In almost all cases it is necessary to examine the isolated sclerites from an octocoral specimen under a compound microscope. See: (http://researcharchive.calacademy.org/research/izg/OctoResearchTech.htm).

It is important to examine an actual specimen as opposed to looking only at an image of an octocoral. Oftentimes, not enough vital information is provided in order to make a dependable identification - such as what the organism looked like in life, at what depth it was collected, from what geographical location it was found, etc. For the most part, positive identifications can only be made after the detailed examination of a specimen has been made. Images usually do not provide enough detail of morphologically important characters for adequate identification purposes. When a tentative or "best guest" identification is made the abbreviation "cf." is often used to denote a tentative or possible identification, from the Latin conferre - to bring together or to compare with. An example would be Virgularia cf. gustaviana, where the genus is known but the species is a best guest or appears closest to V. gustaviana. If a particular species of Virgularia has not been identified to the species level, the notation "sp." is used, as in Virgularia sp. If more than one species of a the genus Virgularia are referred to, the notation "spp." is used, as in Virgularia spp.