Testicle of Fish Under the Microscope
Testicle of Fish (Section), Cyprinus carpio
This is a section of a fish testis stained with H&E. It shows groups of cells at different stages of becoming sperm.
This section of a fish gonad from a common carp (Cyprinus carpio) is stained with H&E. The tissue is folded into lobes that surround a large open space in the middle, with thin pink connective tissue between them. The lobes are packed with round germ cells of many sizes, which stain purple. Many of the larger cells have a big pale nucleus lined with small dark dots. The wide range of sizes shows cells caught at different stages of growth, which students can compare across the slide.
What to look for
- Lobules: Compartments of the testis separated by thin pink connective tissue.
- Cysts: Groups of germ cells inside the lobules, each group at about the same stage.
- Early germ cells: Larger cells with rounder, paler nuclei.
- Late germ cells and sperm: Smaller cells with very dark, compact nuclei, often filling the center of the lobules.
- Sperm duct: A channel where mature sperm collect.
Questions and answers
What does a fish testis look like under a microscope?
A fish testis is divided into compartments filled with groups of germ cells. Each group is at a different stage of development, from larger early cells to small, dark sperm.
Why do sperm cells stain so dark?
As sperm mature, their DNA packs very tightly into a small head. That dense DNA takes up hematoxylin strongly, so sperm heads look very dark purple.
- Category
- Vertebrates
- Scan magnification
- 20x
- Stain
- H&E
Viewing this slide in class
This is a scan of a real prepared slide, not a simulation or a drawing. On StudyScope you can pan from the whole slide down to individual structures, always in focus, and measure them in real micrometers with the calibrated ruler. Present it live and every student screen follows your view and annotations. Students join with a room code on Chromebooks, iPads, or any browser, with no accounts.