Collection Policies

Access to the collection is open to qualified visitors, researchers and students. 

A limited amount of funding is available for researchers to use the collections. The Museum of Comparative Zoology periodically awards Ernst Mayr Grants to systematists who need to make short museum visits in order to undertake research needed for the completion of taxonomic revisions and monographs.


Requests for loans must be made via regular or airmail on institutional letterhead; e-mail requests are not sufficient. Loans are made to institutions under the name of a permanent staff member of the institution. Specimens must not be moved to another address without written permission from MCZ. The major professor or postdoctoral advisor, who will assume legal responsibility for the specimens, must countersign loan requests from students and postdoctoral fellows.

Ordinarily, no more than one-half of the total specimens of a species will be lent at one time. The remainder may be requested after return of the first loan. Series of specimens from single localities may be borrowed as units so long as they do not exceed one-half of the total. Fragile specimens (e.g., certain skeletal and larval materials) will ordinarily not be lent. Requests for types should be made separately and will be considered on a case-by-case basis, with the safety of the specimen of upmost priority.

Requests for permission to dissect or otherwise alter specimens are decided on a case-by-case basis, and must receive prior approval in writing.

All loan requests should be addressed to José Rosado.

Care & Handling

The following guidelines outline the minimum level of care that we expect from researchers studying and borrowing our specimens.

Alcoholic Specimens

Maintain specimens in 70% ethanol. They should not be transferred to any other concentration of ethanol or any other liquid (including isopropanol).

Keep specimens moist during examination. They should be kept moist with 70% ethanol NOT WATER. Never transfer MCZ specimens to water, not even briefly.

Examine specimens with care to avoid damage. Please do not force limbs, jaws, etc. into positions that tear muscles or break bones.

Dissections or Other Specimen Modification

Any dissection of MCZ specimens (including sex determination) requires the written approval of the MCZ curator and/or collections manager. Permission to modify one specimen is not automatically conferred to other specimens. When in doubt, ask.

When permission to determine sex has been given, incisions must be performed to avoid cutting skeletal elements and viscera; incisions should be kept as small as possible. Anurans: Incise the dorsolateral body wall, adjacent to the sacral diapophysis. Salamanders and lizards: Make a midventral incision. Begin at midbody, posterior to sternal elements (including inscriptional ribs), and extend posteriorly to the level of the pubes, where a lateral incision on one side is permitted. Snakes, amphibaenians, and caecilians: Make a short, mid-ventral incision over the gonad region; do not extend the incision from the vent forward to midbody. If the incision gapes open, close it with 1 or 2 suture stitches. If a snake is sexed by hemipenial dissection, the incision should be made to locate only one hemipenis.

In cases where organs are removed for histological examination, the tissue and the finished microscopic slides should be returned to the MCZ upon completion of the study. Stomach contents are also to be returned. Large items may be returned to the stomach; small or large items returned in vials must be labeled accurately with respect to specimen derivation (MCZ number and determination) and identification of contents.

Specimens that are to be cleared and double-stained should have the following additional data recorded by the preparator: snout-vent length, body and tail length (when appropriate), sex and reproductive condition (if possible). Additionally, the skin and viscera are to be returned, properly labeled with the name and number of that specimen.