MSD Manual

Please confirm that you are a health care professional

Yes No
Leave this Site?

The link you have selected will take you to a third-party website. We do not control or have responsibility for the content of any third-party site.

Continue Cancel
honeypot link
MSD Manual
Veterinary Manual
The trusted provider of veterinary information since 1955

Species Filter

Enter search terms to find related veterinary topics, multimedia and more.

Advanced Search:

• Use “ “ for phrases
o [ “canine influenza”]
• Use – to remove results with certain terms
o [pig –guinea]
• Use OR to account for alternate terms
o [alopecia OR “hair loss” ]

VETERINARY PET
Apiosoma, gill, oscar (Astronotus ocellatus)
<i >Apiosoma</i>, gill, oscar (<i >Astronotus ocellatus</i>)
Apiosoma, gill, oscar (Astronotus ocellatus)

    Video of microscopic examination of gill tissue from an oscar (Astronotus ocellatus). Apiosoma is attached to the tip of a primary gill filament. Unstained wet mount; magnification 400×.

Courtesy of Dr. Denise Petty.

Merck & Co., Inc., Rahway, NJ, USA (known as MSD outside of the US and Canada) is dedicated to using leading-edge science to save and improve lives around the world.  The Veterinary Manual was first published in 1955 as a service to the community.  The legacy of this great resource continues in the online and mobile app versions today.

This icon serves as a link to download the eSSENTIAL Accessibility assistive technology app for individuals with physical disabilities. It is featured as part of our commitment to diversity and inclusion.
This icon serves as a link to download the eSSENTIAL Accessibility assistive technology app for individuals with physical disabilities. It is featured as part of our commitment to diversity and inclusion.
Copyright © 2023 Merck & Co., Inc., Rahway, NJ, USA and its affiliates. All rights reserved.