Microscopy Thread

EnterName

Well-Known Member
View Badges
Joined
Sep 21, 2025
Messages
808
Reaction score
1,931
Location
Germany
Rating - 0%
0   0   0
Hello everyone and welcome to this little microscopy thread!

Many hobbyists stumble upon microscopes once they are dealing with a pest they can't properly identify any other way. Besides their obvious usefulness when dealing with a problem, microscopes grant access to a whole new world many people seem to forget about, even though it builds the very foundation of a healthy coral reef.

That's why I decided to start this thread and share some of the microscopy photos I've taken from my reef tank. I'd love for anyone with the ability to capture good microscope images to post theirs as well. If the community enjoys these images, I will try to add more photos/videos here every once in a while.

Fortunately for me (but unfortunately for this thread) I've managed to keep my tank free of major pests, so I can't provide images of things like acropora-eating flatworms, red planaria, and similar troublemakers yet (hopefully it stays that way). I can, however, share photos of various dinoflagellates, diatoms, coral tissue, copepods, and more, if people are interested.

I hope you enjoy the first few images I have taken for this thread:

1. Amphiprion ocellaris (Common Clownfish) eggs.

x50DFFS_Amphiprion_ocellaris_egg_day1.jpg

(Clownfish egg - Day 1)

x100DFFS_Amphiprion_ocellaris_egg_day5.jpg

(Clownfish egg - Day 5)
It is astonishing how much changes within a few days.​


2. Coral samples
Briareum sp.jpg

(Briareum sp. polyp with dense zooxanthellae population)
These little orange circles are most likely Symbiodinium sp. (dinoflagellates) living in symbiosis with their host coral to provide energy via photosynthesis in exchange for anorganic molecules and a safe place to stay.

Rhodactis_sp_Cnidocyte.jpg

(Rhodactis sp. "Rhodactis Plutonium" cnidocytes and some zooxanthellae)
Ever wondered how corals can sting something? These bean shaped cells are everywhere on certain corals and will literally shoot a toxin-loaded string (cnidocyst, well visible on the image) into whatever activates them.

Sclerite.jpg

(Briareum sp. "sclerite")
Even though Briareum is considered a soft coral it still grows these calcitic spicules.
3. Various critters
Ostracod.jpg

(Some Ostracod I found in the stomach of a flatworm)
Harmless armored crusaceans that you can find sifting through detritus in the substrate

Flatworm1.jpg

(Juvenile Ghost Flatworm)
The visible "hole" in its body stems from the previously posted ostracod which simply "fell out" of it after a while of observing it swim around on the slide. This particular species doesn't seem to cause any harm to corals. This specimen was maybe 1mm in length, but they can grow up to like 4mm.
4. Algae and Protists
Ostreopsis_Cropped.jpg

(Dinoflagellate, probably Ostreopsis sp.)
One of the more dangerous dinoflagellates due to toxicity according to the identification guide, but finding a few single cells from time to time is absolutely normal and nothing to worry about.

Prorocentrum.jpg

(Dinoflagellate, probably Prorocentrum sp., maybe P. lima?)
These guys appear to be preying on diatoms, at least their number seems somewhat proportional to the diatom population in my tank. They never become a problem and I only see very small numbers of them, but if my tank would at some point get a dino issue, I'm pretty sure it will be those guys.

Marine_Diatom_Licmophora.jpg

(Diatom, possibly Licmophora sp.)
These little guys are very abundant in my tank. They attach to pretty much every surface they can find and make up a major portion of the stuff that needs to be scraped off of my tank glass frequently. My copperband butterfly fish for some reason loves eating the brown stuff coming off my glass while I clean it.


Equipment
Most images are taken with my Leica/Leitz DMRB microscope using DIC microscopy and focus stacking (some are dark-field or simple bright-field). I'm currently using a Sony A7iii to take images and will hopefully soon get my hands on some better microscope objectives so quality improves further. The images you have seen range from 50x to 1000x magnification.

Further Posts:
Amphidinium small cell (Page 1, Post #3)
[Video] Polychaete in dark field (Page 1, Post #4)
[Video] Parenchymella larvae of a sponge (Page 1, Post #6)
Bubble algae (Page 1, Post #8)
Copepod nauplii (Page 1, Post #11)
[Video] Some unidentified "worm" (Page 1, Post #12)
Diatoms (Page 1, Post #16)
[Video] Some Sabellidae or Serpulidae tube-worm in DIC (Page 2, Post #24)
 
Last edited:

Euphyllia97

FOWLR and reef member
View Badges
Joined
Oct 22, 2019
Messages
1,026
Reaction score
1,493
Location
Belgium
Rating - 0%
0   0   0
Copepod and a sample of green algae during my “uglies” phase. Would love to see some parasites on this topic :)
 

Attachments

  • IMG_0216.jpeg
    IMG_0216.jpeg
    74.8 KB · Views: 70
  • IMG_0179.jpeg
    IMG_0179.jpeg
    161.5 KB · Views: 70
OP
OP
EnterName

EnterName

Well-Known Member
View Badges
Joined
Sep 21, 2025
Messages
808
Reaction score
1,931
Location
Germany
Rating - 0%
0   0   0
Found a small Amphidinium sp. cell. I hope quality improves with new objectives soon, but the small cells will always be a challenge to properly capture.
Amphidinium_Small.jpg
 

nitrox2000

New Member
View Badges
Joined
Mar 21, 2025
Messages
21
Reaction score
32
Location
Devon
Rating - 0%
0   0   0
The below images are thought to be an Amphidinium species of Dinoflagellates, although not the common variety usually found as it doesn't have a hook like mouth:

2.JPG


3.JPG


The below image is a more common Amphidinium, with a visible hook like mouth:

Capture.JPG


I have a attached a few videos below on the behaviour and swim patterns:





 
OP
OP
EnterName

EnterName

Well-Known Member
View Badges
Joined
Sep 21, 2025
Messages
808
Reaction score
1,931
Location
Germany
Rating - 0%
0   0   0
Here is what I assume to be a Parenchymella larvae of some sponge (Porifera sp.) annoying a little copepod.
 
Last edited:
OP
OP
EnterName

EnterName

Well-Known Member
View Badges
Joined
Sep 21, 2025
Messages
808
Reaction score
1,931
Location
Germany
Rating - 0%
0   0   0
I smashed a bubble algae (seed bubble?) Between two slides 20251024_152107.jpg
I liked the idea so I decided to try the same at 400x magnification. The bubble itself has a weird "woven" texture (or messes with DIC microscopy) which I though was really fascinating.
400.jpg

400x.jpg
 

Fish Fan

Master of Disaster
View Badges
Joined
Dec 8, 2017
Messages
12,905
Reaction score
33,603
Location
461 Ocean Boulevard
Rating - 100%
6   0   0
Following
 
OP
OP
EnterName

EnterName

Well-Known Member
View Badges
Joined
Sep 21, 2025
Messages
808
Reaction score
1,931
Location
Germany
Rating - 0%
0   0   0
Nauplii.jpg

(Copepod nauplii)​
I think there is room for improvement, but still a decent image for identification purposes if someone wonders what is "jumping" around under their microscope :)
These little guys are quite fast and it isn't too easy creating focus stack images of them.
 
OP
OP
EnterName

EnterName

Well-Known Member
View Badges
Joined
Sep 21, 2025
Messages
808
Reaction score
1,931
Location
Germany
Rating - 0%
0   0   0

I wasn't able to fully identify this little guy. It seems to be some annelid. It looks like a Polychaete larvae (or rather a Nectochaete), but the bristles (namely "chaetigers") seem to be missing.​
 
OP
OP
EnterName

EnterName

Well-Known Member
View Badges
Joined
Sep 21, 2025
Messages
808
Reaction score
1,931
Location
Germany
Rating - 0%
0   0   0
Love these! I’ve always wanted a decent microscope
Glad you like the images and videos :)

You don't need an expensive microscope to see/identify the things posted here. You can enjoy the micro-cosmos in your tank (or ponds, puddles, and more) with something between $50 and $200 just fine.

However, you will be limited to bright-field microscopy (background is white/bright and specimens appear flat). Dark-field is affordable, but will already cost a bit more (background is black/dark and specimens appear illuminated like for example the clownfish eggs). If you also want this 3D-Effect where specimens appear to cast a shadow (Differential Interference Contrast), it will get really expensive.

Just start cheap and see if this is something you want to keep doing.
 
OP
OP
EnterName

EnterName

Well-Known Member
View Badges
Joined
Sep 21, 2025
Messages
808
Reaction score
1,931
Location
Germany
Rating - 0%
0   0   0
DSC08981.jpg

(More diatoms, but I don't know the genus or species yet. Maybe something like Cylindrotheca closterium?)​

Besides the already posted Licmophora sp (the pizza slice shaped diatom), these are the dominant diatoms in my tank and move around quite a lot, so it is not always easy to get a decent photo-stack image. They are also really thin, so we are already pushing what a light-microscope can resolve.
 

Dom

Theoretical Reef Keeper
View Badges
Joined
Apr 29, 2016
Messages
7,753
Reaction score
8,190
Location
NY
Rating - 0%
0   0   0
1. Amphiprion ocellaris (Common Clownfish) eggs.
x50DFFS_Amphiprion_ocellaris_egg_day1.jpg

(Clownfish egg - Day 1)

x100DFFS_Amphiprion_ocellaris_egg_day5.jpg

(Clownfish egg - Day 5)
It is astonishing how much changes within a few days.


These Clownfish egg photos are fascinating. But the story is incomplete. 😉

I would have enjoyed seeing the complete progression.

Thank you for sharing!

Dom
 
OP
OP
EnterName

EnterName

Well-Known Member
View Badges
Joined
Sep 21, 2025
Messages
808
Reaction score
1,931
Location
Germany
Rating - 0%
0   0   0
These Clownfish egg photos are fascinating. But the story is incomplete. 😉

I would have enjoyed seeing the complete progression.

Thank you for sharing!

Dom
That's a fair point, unfortunately I can't raise Clownfish babies right now and don't know if I can start another giant project :D

Would be really cool though, and I have been thinking about it a lot... Maybe some day :)
 

TheMachinistReefer

New Member
View Badges
Joined
Dec 18, 2025
Messages
8
Reaction score
27
Location
USA
Rating - 0%
0   0   0
I've recently discovered how fascinating this side of the hobby is. I just have a cheap microscope, but it does the job!
 

Attachments

  • 20251031_165646.mp4
    35.2 MB
OP
OP
EnterName

EnterName

Well-Known Member
View Badges
Joined
Sep 21, 2025
Messages
808
Reaction score
1,931
Location
Germany
Rating - 0%
0   0   0
I've recently discovered how fascinating this side of the hobby is. I just have a cheap microscope, but it does the job!
Ostreopsis aside, I like the large diatoms. Is it a young tank or did you manage to maintain their population somehow? In my tank diatom diversity has declined over the years and I would really like to understand how to get some of these larger diatoms back.
 

TOP 10 Trending Threads

WHAT AMOUNT OF LIVE ROCK AND SAND SHOULD BE PRIORITIZED FOR OPTIMAL BIODIVERSITY/FILTRATION?

  • 100% live rock + bagged sand

    Votes: 34 27.6%
  • 100% dry rock + 100% live sand

    Votes: 43 35.0%
  • 50/50 live/dry rock, 50/50 live/bagged sand

    Votes: 27 22.0%
  • 75% live rock, 25% live sand

    Votes: 11 8.9%
  • 25% live rock, 75% live sand

    Votes: 8 6.5%
Back
Top