Microscopy Thread

[EnterName]

Cat Nudibranch
(Vayssierea sp.)

Note: If you are using the app you might need to switch to a webbrowser to be able to see the video(s).​

I received some new frags today and during the coral dip I noticed a tiny red spot on an acropora frag. I was really worried to have found an Acropora Red Bug (Tegastes acroporanus) or Red Planaria (Convolutriloba retrogemma), but apparently it's a little sea slug.

(Recorded with Smartphone camera and macro lens)
​

Common Name	Cat Nudibranch
Classification	Vayssierea sp. possibly Vayssierea felis?
Verdict	Neutral - Harmless
Size	≤ 6mm (0.24")
Found	?
Rarity	Rare

(Here is a bright-field recording of the slug. Unfortunately the depth of field is very limited)
​

I assume it is a Cat Nudibranch (Vayssierea felis) which eats Spirorbis (see post #81), and Salmacina tubeworms. The only odd thing about this specimen is that I can only see one Rinophore (olfactorive organ)... Maybe I am completely missing something or it's just an oddity of this specific slug like a birth defect or an injury.

@ISpeakForTheSeas, there you have it. You said you liked being tagged, now you have to deal with the consequences

I wasn't sure about my suggested identification so I placed the slug into a beaker with some tank water and a few spirorbid worms. After not showing too much interest for like 5 hours it is sitting on one of the spirorbid shells now. This is giving me some confidence that it's indeed a Vayssierea species and I can safely add it to my filter sump.

 

[EnterName]

Tanaid?
(Order: Tanaidacea?)

Note: If you are using the app you might need to switch to a webbrowser to be able to see the video(s).

(A quite bad macro shot of what I'm assuming to be a Tanaid just like in post #40, maybe 4mm/0.16" in length. As you might have noticed I often come back to older posts to add images or replace bad recordings. I hopefully will have the opportunity to do this here as well, but for now this little guy is back in my tank)​

Common Name	Tanaid?
Classification	Order: Tanaidacea?
Verdict	Harmless
Size	≤ 6mm (0.24")
Found	Rockscape or buried in
Rarity	Common (in nearly all tanks, but often live hidden)

I got very lucky with the specimen today. It was really calm and just sat still in a single spot without moving, which made taking photos and videos easier.

(Head)

(Middle section)​

In contrast to many other crustaceans, Tanaids don't drift off as free-swimming larvae. This creates genetically isolated populations over time which might have contributed to the fact that there are so many localized species, and it might also be the reason why these guys manage to reproduce in tanks and don't simply end up in the skimmer as larvae.

(You can see the crustaceans equivalent of blood cells called "Hemocytes" flowing through its body)

(Middle section with clearly visible "heartbeat")​

 

[EnterName]

Zoospores of Green Hair Algae
(No specific species)

Note: If you are using the app you might need to switch to a webbrowser to be able to see the video(s).​

Most people are quite familiar with green nuisance algae that can grow pretty much everywhere in a tank. What they might be less familiar with are zoospores.

(This is actually a freshwater GHA species, but I really like the image I struggle to find a good-looking green hair algae in my tank, so this will have to do for now)​

Common Name	Zoospores
Classification	Depends on the releasing algae
Verdict	Undesired but unavoidable (cause algae to spread)
Size	≤ 30μm
Found	Algae samples
Rarity	Unavoidable, but depends on algae presence in tank

Zoospores are one of multiple ways algae can reproduce asexually which means they don't require a mate to create offspring. These spores are stored in so called Zoosporangia:

(Zoosporangium of a marine green hair algae species containing zoospores)​

There are multiple forms of Zoosporangia, but the ones I found simply pop open once the conditions are right and release the contained zoospores. I assume it's some Derbesia sp., but I'm not sure.

(Zoospores tend to be in constant movement making it really difficult to get proper footage)​

If you have a microscope and want to observe this yourself you can simply put some hair algae on a slide and keep waiting. In my experience the evaporation of water from the sample will cause algae to release zoospores sooner or later.

 

[Subsea]

Reef2Reef Microscopy Thread ​

Your tank is packed with life you might have never noticed: rotifers, protists, larval worms, sponges, micro algae, etc. Most of it is smaller than a grain of salt but still absolutely fascinating. This thread is where the Reef2Reef community can take a closer look at what lives "hidden" in our tanks.

Using DIC microscopy, a technique that turns transparent, near-invisible critters into glowing 3D sculptures of light and shadow, I'll be posting high-res images and videos of whatever's crawling, swimming, or drifting through our reef tanks. Everyone is invited to share their microscopy images/videos as well!

No Microscope? No problem. You don't need one to enjoy this thread nor to pursue the hobby. It can be a lot of fun though and help with the proper identification of what you are dealing with.

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

1. Amphiprion ocellaris (Common Clownfish) eggs.

(Clownfish egg - Day 1)

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

2. Coral samples

(Briareum sp. polyp with dense zooxanthellae population)
These little orange circles are 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. Most of you may know them as "zooxanthellae".

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

(Briareum sp. "sclerite")
Even though Briareum spp. are considered a soft coral they still grow these calcitic spicules that act as a skeleton. These are mainly found in the tissue that is growing on the rocks and holds the polyps in place.
​

3. Various critters

(Some Ostracod I found in the stomach of a flatworm)
Armored crusaceans that you can find sifting through detritus in the substrate. They can look a bit creepy when moving around, but they are beneficial and harmless.

(Juvenile Flatworm. This specimen should be an "Acoel Flatworm". They can be distinguished from "Ghost Flatworms" by their darker coloration caused by their Zooxanthellae. See post #85)
There are thousands of different flatworm species, most of them aren't welcome in a reef tank, but these ones are "ok". Their population can explode and they eat copepods, but at least they don't harm corals, fish, or inverts. This specimen was maybe 1mm in length, but they can grow up to like 4mm.
​

4. Algae and Protists

(Dinoflagellate, probably Ostreopsis sp.)
One of the more dangerous dinoflagellates due to its toxicity, but finding a few single cells from time to time is absolutely normal and nothing to worry about. I had quite a lot of them for some time, but the toxin never really became an issue. My copperband butterflyfish even ate a lot of them every time I scraped the glass clean. I frequently found them together with diatoms.

(Dinoflagellate, probably Prorocentrum sp., maybe P. lima?)
Another dinoflagellate species I had a lot of for some time. Their numbers grew proportional to the diatom population which might suggest they are preying on diatoms or simply thrive in the same environments.

(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.


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 microscopy images though). I'm currently using a Sony A7iii to take images in a magnification range from 50x to 1000x.

Table of Contents​

Posts (ordered by date):
[Photo+Video] Amphidinium sp. (Page 1, Post #3)
[Video] Polychaete (Page 1, Post #4)
[Video] Parenchymella larvae of a sponge (Page 1, Post #6)
[Photo] Bubble algae (Page 1, Post #8)
[Photo] Copepod nauplii (Page 1, Post #11)
[Video] Some unidentified "worm" (Page 1, Post #12)
[Photo+Video] Diatoms, likely Nitzschia sp. (Page 1, Post #16)
[Video] Sabellidae or Serpulidae tube-worm (Page 2, Post #24)
[Video] Unknown specimen & possibly tubeworm larvae (Page 2, Post #39)
[Video] Collection of short clips (Page 2, Post #40)
[Video] Unidentified, most likely Trachelocercid ciliate (Page 3, Post #46)
[Video] Spawning Rock Anemone + Gametes (Page 3, Post #50)
[Video] Hydroid Medusa (Page 3, Post #51)
[Video] Cyanobacterium (Spirulina sp.?) (Page 3, Post #52)
[Photo] Branched Halymenia (Halymenia durvillei) (Page 3, Post #60)
[Video] Digitate Hydroid (Page 4, Post #61)
[Photo] Ball Sponges (Tethya sp.?) (Page 4, Post #68)
[Photo] Sea lettuce (Ulva or Ulvaria sp.) (Page 4, Post #69)
[Photo+Video] Hydroid, possibly Obelia sp. (Page 4, Post #80)
[Photo+Video] Spirorbid worm (Page 5, Post #81)
[Photo+Video] Sponge, possibly Clathrina sp. (Page 5, Post #82)
[Photo+Video] Pineapple Sponge, Sycon sp. (Page 5, Post #83)
[Video] Unknown specimen (Page 5, Post #84)
[Photo+Video] Acoel Flatworm (Heterochaerus sp.?) (Page 5, Post #85)
[Photo] Unidentified diatoms (Page 5, Post #91)
[Photo+Video] Nematodes (Page 5, Post #92)
[Video] Trachelocercidae Ciliate? (Page 5, Post #93)
[Photo] Unidentified specimen (Page 5, Post #94)
[Video] Euplotida Ciliate (Page 5, Post #100)
[Video] Cat Sea Slug (Vayssierea felis)? (Page 6, Post #101)

Posts (ordered by specimen):

Red & Green Algae
[Photo] Bubble algae (Page 1, Post #8)
[Photo] Branched Halymenia (Halymenia durvillei) (Page 3, Post #60)
[Photo] Sea lettuce (Ulva or Ulvaria sp.) (Page 4, Post #69)

Bacteria
[Video] Cyanobacterium (Spirulina sp.?) (Page 3, Post #52)

Ciliates
[Video] Trachelocercidae Ciliate? (Page 5, Post #93)
[Video] Euplotida Ciliate (Page 5, Post #100)

Coral samples
[Video] Spawning Rock Anemone + Gametes (Page 3, Post #50)

Diatoms
[Photo] Licmophora sp. (Page 1, Post #1, this very post)
[Photo+Video] Diatoms, likely Nitzschia sp. (Page 1, Post #16)
[Photo] Unidentified diatoms (Page 5, Post #91)

Dinoflagellates & Protists
[Photo] Prorocentrum sp. & Ostreopsis sp. (Page 1, Post #1, this very post)
[Photo+Video] Amphidinium sp. (Page 1, Post #3)

Hydroids
[Video] Hydroid Medusa (Page 3, Post #51)
[Video] Digitate Hydroid (Page 4, Post #61)
[Photo+Video] Hydroid, possibly Obelia sp. (Page 4, Post #80)

Sponges
[Photo] Ball Sponges (Tethya sp.?) (Page 4, Post #68)
[Photo+Video] Root-like growing sponge, possibly Clathrina sp. (Page 5, Post #82)
[Photo+Video] Pineapple Sponge, Sycon sp. (Page 5, Post #83)

Worms
[Video] Polychaete (Page 1, Post #4)
[Video] Some unidentified "worm" (Page 1, Post #12)
[Video] Sabellidae or Serpulidae tubeworm (Page 2, Post #24)
[Photo+Video] Spirorbid worm (Page 5, Post #81)
[Photo+Video] Acoel Flatworm (Heterochaerus sp.?) (Page 5, Post #85)
[Photo+Video] Nematodes (Page 5, Post #92)

Other
[Video] Parenchymella larvae of a sponge (Page 1, Post #6)
[Photo] Copepod nauplii (Page 1, Post #11)
[Video] Unknown specimen & possibly tubeworm larvae (Page 2, Post #39)
[Video] Collection of short clips (Page 2, Post #40)
[Video] Unidentified, most likely Trachelocercid ciliate (Page 3, Post #46)
[Video] Unknown specimen (Page 5, Post #84)
[Photo] Unidentified specimen (Page 5, Post #94)
[Video] Cat Sea Slug (Vayssierea felis)? (Page 6, Post #101)

What an interesting thread! Thank you for doing this.

 

[EnterName]

Reef2Reef Microscopy Thread ​

Your tank is packed with life you might have never noticed: rotifers, protists, larval worms, sponges, micro algae, etc. Most of it is smaller than a grain of salt but still absolutely fascinating. This thread is where the Reef2Reef community can take a closer look at what lives "hidden" in our tanks.

Using DIC microscopy, a technique that turns transparent, near-invisible critters into glowing 3D sculptures of light and shadow, I'll be posting high-res images and videos of whatever's crawling, swimming, or drifting through our reef tanks. Everyone is invited to share their microscopy images/videos as well!

No Microscope? No problem. You don't need one to enjoy this thread nor to pursue the hobby. It can be a lot of fun though and help with the proper identification of what you are dealing with.

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

1. Amphiprion ocellaris (Common Clownfish) eggs.

(Clownfish egg - Day 1)

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

2. Coral samples

(Briareum sp. polyp with dense zooxanthellae population)
These little orange circles are 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. Most of you may know them as "zooxanthellae".

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

(Briareum sp. "sclerite")
Even though Briareum spp. are considered a soft coral they still grow these calcitic spicules that act as a skeleton. These are mainly found in the tissue that is growing on the rocks and holds the polyps in place.
​

3. Various critters

(Some Ostracod I found in the stomach of a flatworm)
Armored crusaceans that you can find sifting through detritus in the substrate. They can look a bit creepy when moving around, but they are beneficial and harmless.

(Juvenile Flatworm. This specimen should be an "Acoel Flatworm". They can be distinguished from "Ghost Flatworms" by their darker coloration caused by their Zooxanthellae. See post #85)
There are thousands of different flatworm species, most of them aren't welcome in a reef tank, but these ones are "ok". Their population can explode and they eat copepods, but at least they don't harm corals, fish, or inverts. This specimen was maybe 1mm in length, but they can grow up to like 4mm.
​

4. Algae and Protists

(Dinoflagellate, probably Ostreopsis sp.)
One of the more dangerous dinoflagellates due to its toxicity, but finding a few single cells from time to time is absolutely normal and nothing to worry about. I had quite a lot of them for some time, but the toxin never really became an issue. My copperband butterflyfish even ate a lot of them every time I scraped the glass clean. I frequently found them together with diatoms.

(Dinoflagellate, probably Prorocentrum sp., maybe P. lima?)
Another dinoflagellate species I had a lot of for some time. Their numbers grew proportional to the diatom population which might suggest they are preying on diatoms or simply thrive in the same environments.

(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.


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 microscopy images though). I'm currently using a Sony A7iii to take images in a magnification range from 50x to 1000x.

Table of Contents​

Posts (ordered by date):
[Photo+Video] Amphidinium sp. (Page 1, Post #3)
[Video] Polychaete (Page 1, Post #4)
[Video] Parenchymella larvae of a sponge (Page 1, Post #6)
[Photo] Bubble algae (Page 1, Post #8)
[Photo] Copepod nauplii (Page 1, Post #11)
[Video] Some unidentified "worm" (Page 1, Post #12)
[Photo+Video] Diatoms, likely Nitzschia sp. (Page 1, Post #16)
[Video] Sabellidae or Serpulidae tube-worm (Page 2, Post #24)
[Video] Unknown specimen & possibly tubeworm larvae (Page 2, Post #39)
[Video] Collection of short clips (Page 2, Post #40)
[Video] Unidentified, most likely Trachelocercid ciliate (Page 3, Post #46)
[Video] Spawning Rock Anemone + Gametes (Page 3, Post #50)
[Video] Hydroid Medusa (Page 3, Post #51)
[Video] Cyanobacterium (Spirulina sp.?) (Page 3, Post #52)
[Photo] Branched Halymenia (Halymenia durvillei) (Page 3, Post #60)
[Video] Digitate Hydroid (Page 4, Post #61)
[Photo] Ball Sponges (Tethya sp.?) (Page 4, Post #68)
[Photo] Sea lettuce (Ulva or Ulvaria sp.) (Page 4, Post #69)
[Photo+Video] Hydroid, possibly Obelia sp. (Page 4, Post #80)
[Photo+Video] Spirorbid worm (Page 5, Post #81)
[Photo+Video] Sponge, possibly Clathrina sp. (Page 5, Post #82)
[Photo+Video] Pineapple Sponge, Sycon sp. (Page 5, Post #83)
[Video] Unknown specimen (Page 5, Post #84)
[Photo+Video] Acoel Flatworm (Heterochaerus sp.?) (Page 5, Post #85)
[Photo] Unidentified diatoms (Page 5, Post #91)
[Photo+Video] Nematodes (Page 5, Post #92)
[Video] Trachelocercidae Ciliate? (Page 5, Post #93)
[Photo] Unidentified specimen (Page 5, Post #94)
[Video] Euplotida Ciliate (Page 5, Post #100)
[Video] Cat Sea Slug (Vayssierea felis)? (Page 6, Post #101)

Posts (ordered by specimen):

Red & Green Algae
[Photo] Bubble algae (Page 1, Post #8)
[Photo] Branched Halymenia (Halymenia durvillei) (Page 3, Post #60)
[Photo] Sea lettuce (Ulva or Ulvaria sp.) (Page 4, Post #69)

Bacteria
[Video] Cyanobacterium (Spirulina sp.?) (Page 3, Post #52)

Ciliates
[Video] Trachelocercidae Ciliate? (Page 5, Post #93)
[Video] Euplotida Ciliate (Page 5, Post #100)

Coral samples
[Video] Spawning Rock Anemone + Gametes (Page 3, Post #50)

Diatoms
[Photo] Licmophora sp. (Page 1, Post #1, this very post)
[Photo+Video] Diatoms, likely Nitzschia sp. (Page 1, Post #16)
[Photo] Unidentified diatoms (Page 5, Post #91)

Dinoflagellates & Protists
[Photo] Prorocentrum sp. & Ostreopsis sp. (Page 1, Post #1, this very post)
[Photo+Video] Amphidinium sp. (Page 1, Post #3)

Hydroids
[Video] Hydroid Medusa (Page 3, Post #51)
[Video] Digitate Hydroid (Page 4, Post #61)
[Photo+Video] Hydroid, possibly Obelia sp. (Page 4, Post #80)

Sponges
[Photo] Ball Sponges (Tethya sp.?) (Page 4, Post #68)
[Photo+Video] Root-like growing sponge, possibly Clathrina sp. (Page 5, Post #82)
[Photo+Video] Pineapple Sponge, Sycon sp. (Page 5, Post #83)

Worms
[Video] Polychaete (Page 1, Post #4)
[Video] Some unidentified "worm" (Page 1, Post #12)
[Video] Sabellidae or Serpulidae tubeworm (Page 2, Post #24)
[Photo+Video] Spirorbid worm (Page 5, Post #81)
[Photo+Video] Acoel Flatworm (Heterochaerus sp.?) (Page 5, Post #85)
[Photo+Video] Nematodes (Page 5, Post #92)

Other
[Video] Parenchymella larvae of a sponge (Page 1, Post #6)
[Photo] Copepod nauplii (Page 1, Post #11)
[Video] Unknown specimen & possibly tubeworm larvae (Page 2, Post #39)
[Video] Collection of short clips (Page 2, Post #40)
[Video] Unidentified, most likely Trachelocercid ciliate (Page 3, Post #46)
[Video] Unknown specimen (Page 5, Post #84)
[Photo] Unidentified specimen (Page 5, Post #94)
[Video] Cat Sea Slug (Vayssierea felis)? (Page 6, Post #101)

What an interesting thread! Thank you for doing this.

Thank you so much for the kind words!

I'm currently upgrading my microscope with pretty much the best objectives I can get. I will revisit old posts and replace or add images if I manage to get better ones over time.

Maybe I will also buy some new live rock just to see what else I can find on them. Once I have a decent collection I might summarize it into a single post or article so people can use it to identify what's in their tank without having to skip through numerous pages. We will see

All kinds of contributions are welcome, if you know more about a posted specimen or have some nice microscopy images yourself, you are more than welcome to share them here!

Some posts and the videos are unfortunately broken in the R2R app. I'm hoping the staff will figure out how to solve these issues so everyone can enjoy the posts again. Videos don't show up and text will suddenly stop mid sentence when some links are added. I'm working through the posts to find a workaround but it's not always possible.

 

[EnterName]

Munnidae Isopod
(Family: Munnidae)

Note: If you are using the app you might need to switch to a webbrowser to be able to see the videos.​

I should have posted these far earlier, but after switching tanks they preferred to stay on the rocks instead of climbing on the glass making it difficult to catch one. Today I got lucky though.

(Isopod sitting on the tank glass. Another bad macro lens shot )​

Common Name	Isopod "pod"
Classification	Family: Munnidae
Verdict	Beneficial
Size	≤ 4mm (0.16")
Found	Glass, Detritus, Macro algae, Coral skeleton
Rarity	Common (found in most tanks)

(Amphipod sitting on microscope slide)
​

If you want to observe one under your microscope yourself you need to make sure to elevate the cover glass or you will squash it. I use petroleum jelly on the edges of the cover glass to keep the sample from drying out and make sure the cover glass doesn't squash larger specimen. You can also place a cover glass left and right from the sample and put a third on top like a little bridge. This should help to prevent squashing them as well.

(Head section)

(Mid section)

(Tail section)
​