The most common and most likely answer to this crossword clue is the 5 letter word ALGAE
I've seen this crossword clue in The Daily Telegraph
A
L
G
A
E
More clues leading to the result ALGAE
- A bird of prey almost picked up fish food?
- Some local Gaelic seaweeds perhaps
- A short bird hauled up deep plants
- Weeds, advanced, big bird mostly pulled up
- Found in tea glass, we should be sent back!
- Scum or gas mostly contaminated beer
- Aquatic life in Portuguese region avoiding river valley primarily
- A predator nearly pulled up seaweed, etc
- Little living things Georgia found in beer
- Small organisms Georgia found in drink
Buddy explains!

The straight part
We know that "Small organisms" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case small organisms = algae.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does ALGAE mean?
ALGAE noun- Any of many aquatic photosynthetic organisms, including the seaweeds, whose size ranges from a single cell to giant kelps and whose biochemistry and forms are very diverse, some being eukaryotic.
- Algal organisms viewed collectively or as a mass; algal growth.
- A particular kind of algae.