File:Astyanax fasciatus (Mexican blind cavefish) 3.jpg
Original file (3,079 × 1,630 pixels, file size: 2.92 MB, MIME type: image/jpeg)
Captions
Captions
Summary[edit]
_3.jpg&action=edit§ion=1){kind=link}
| Description |
English: Astyanax fasciatus (Cuvier, 1819) (or Astyanax mexicanus (De Filippi, 1853), depending on one's taxonomic preferences) - Mexican blind cavefish (captive, American Cave Museum, Horse Cave, Kentucky, USA).
Many caves are known to have blind fish in subterranean bodies of water. Members of several unrelated families have become blind cavefish. This is the Mexican blind cavefish, Astyanax fasciatus (sensu lato), which has been recorded from throughout Central America. It completely lacks eyes (eyes are useless in a permanently dark environment) and also has no pigmentation (hence the pinkish color from blood). However, this species does still possess the genes for eyes. Why? It’s ancestors did have eyes - they’ve been lost through evolution. This is the ultimate fate for all vestigial organs. However, the genes for lost structures are often retained for long geologic intervals of time (for example, chickens still have genes that code for teeth, despite the lack of teeth in chicken beaks). Published research has shown that young cavefish of this species do have functioning eyes and have a light-sensitive area in their brains. The eyes degenerate with ontogeny, as does the light-sensitive area in the brain. Adults have zero light sensing ability. Classification: Animalia, Chordata, Vertebrata, Actinopterygii, Cypriniformes, Characoidei, Characidae |
| Date | |
| Source | https://www.flickr.com/photos/47445767@N05/52554859633/ |
| Author | James St. John |
Licensing[edit]
_3.jpg&action=edit§ion=2){kind=link}
- You are free:
- to share – to copy, distribute and transmit the work
- to remix – to adapt the work
- Under the following conditions:
- attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
|
This image was originally posted to Flickr by James St. John at https://flickr.com/photos/47445767@N05/52554859633. It was reviewed on 12 December 2022 by FlickreviewR 2 and was confirmed to be licensed under the terms of the cc-by-2.0. |
File history
Click on a date/time to view the file as it appeared at that time.
| Date/Time | Thumbnail | Dimensions | User | Comment | |
|---|---|---|---|---|---|
| current | 01:57, 12 December 2022 | | 3,079 × 1,630 (2.92 MB) | Ser Amantio di Nicolao (talk | contribs) | Uploaded a work by James St. John from https://www.flickr.com/photos/47445767@N05/52554859633/ with UploadWizard |
You cannot overwrite this file.
File usage on Commons
There are no pages that use this file.
_3.jpg&oldid=846221376){kind=link}