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Smithsonian National Museum of Natural History
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Department of Vertebrate Zoology

Division of Amphibians & Reptiles

Hyalinobatrachium pellucidum
Hyalinobatrachium pellucidum Ecuador, Napo Province. Photographed by Roy McDiarmid

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

Dissections or Other Modifications

1. Any dissection of USNM specimens (including sex determination) requires the written approval of an USNM curator.  Permission to modify one specimen is not automatically conferred to other specimens.  When in doubt, ask.

2. When permission for sexing has been given, incisions must be performed to avoid cutting skeletal elements and viscera; incisions should be kept as small as possible.

  • Anurans:  incision on dorsolateral body wall, adjacent to the sacral diapophysis.

  • Salamanders & Lizards:  midventral incision beginning midbody (but posterior to stermal elements including inscriptional ribs, extending posteriorly to pubes, here a lateral incision on one side is permitted.

  • Snakes, Amphisbaenians, & Caecillians:  short midventral incision over the gonad region; do not extend incision from vent forward to midbody.  If incision remains open, close with 1 or 2 suture stitches.  If a snake is sexed by hemipenial dissection, the incision should be made to locate only one hemipenis.

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

Alcoholic Specimens

1. Specimens are maintained in 70% ethanol.  They should not be transferred to any other concentration of ethanol or any other liquid (including isopropanol).

2. Specimens should be kept moist during examination.  They should be kept moist with 70% ethanol – NOT WATER.  Never transfer USNM specimens to water, not even briefly!

3. Specimen examination should be done with care to avoid damage.  Please do not force limbs, jaws, etc. into positions that tear muscles or break bones.



(rev. Jul 2018)

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