General observations and dissections were made under a Leica MZ95 stereomicroscope. Microstructures of the dissected parts in pure glycerin were studied under an Olympus BH-2 compound microscope. After observation, the dissected parts were mounted on the same card with the specimen. Photographs were taken under the Leica MZ95 and combined in Helicon Focus ver. 4.70.5 Pro (Helicon Soft Limited).
Morphological terminology follows Hernando and Ribera (2005) . Morphological abbreviations used in the measurements are as follows:
The average is given in parentheses after the range.