Blenny Breeding/ in Home Aquaculture Setup

[MidasBlennyGuy]

This is my first time posting on this forum so first off HELLO!

I have been fascinated with photographing and documenting fish doing courtship behaviors and colorations. My latest endeavour is the Midas Blenny since there is very little online about their mating besides the fact they follow the trend of male protecting the eggs laid in their cave/hole in the reef. I did find a video online of a diver who videotaped courtship in the wild and it got me hooked to see if i could get a better picture in an aquarium setting. I set up a 90 gallon bare bottom tank with live rocks and PVC to give the blennies places to hide and nest in. I have now observed the male showing courtship colors and discovered eggs in one of the PVC pipes and the male is guarding it constantly. Does anyone have any advice on how to potentially collect the eggs and try to raise the larvae? Is there a suggested feed like phyto? any advice would be appreciated.

 

[ISpeakForTheSeas]

Welcome to Reef2Reef!

Midas Blennies (Escenius midas) are likely going to be a tough one to figure out how to raise, but I think we can figure out a few things to at least get the community started here.

I have now observed the male showing courtship colors and discovered eggs in one of the PVC pipes and the male is guarding it constantly. Does anyone have any advice on how to potentially collect the eggs

If the eggs are laid on the PVC pipe, then the easiest way to collect them would be by waiting until shortly before they should hatch on the night they're going to hatch (may vary a bit with temperature, but it should be after lights out ~5 days after laying from what I can find), then swapping out the PVC in the broodstock tank for another piece that looks the same while moving the eggs to a larval rearing tank.

These guys should lay eggs pretty regularly (with only a few days between each spawn, from what I can find), so if you don't succeed with this first batch, you should have plenty of chances to try again (and the more info you can get and share here, the better).

Is there a suggested feed like phyto?

Phyto isn't really used for feeding the fish larvae themselves - it's more used to feed things like copepods, rotifers, and Artemia (Brine Shrimp) which in turn are used to feed the fish larvae.

With Midas Blennies, I know that L-Strain Rotifers have been tried without success, and with other blennies of the same genus (E. bicolor and E. gravieri), I've heard of S-Strain Rotifers and Apocyclops panamensis copepods being used unsuccessfully as well. Given that the larvae are way too small for Artemia nauplii and that the only species in the genus which I can find has confirmedly been reared so far is E. gravieri (reared by ORA), I'd guess it's safe to assume these need either difficult feeders, or feeders not generally available to hobbyists.

So, a good place to start would be with Parvocalanus crassirostris (cultured with/fed Isochrysis galbana/T-Iso), and if that doesn't work there are a few more that can be tried (like Oithona colcarva), but they're a lot more work to get a culture of because they're not sold as individual cultures to the public.

try to raise the larvae?

Here's my advice for this - a quick summary, then the more detailed stuff:

-Setup a little, simple tank.
(The larval rearing tank).

-Add the larvae.

-Add the larval food and enough phytoplankton to tint the water green.
(The phytoplankton helps dim the lighting so it's not too bright for sensitive larvae, it makes it easier for the larvae to see the feeders, and it gutloads the feeders so they're more nutritious when eaten).

-Adjust feeding as needed as the larvae grow; you typically should start feeding regular fish food in addition to the larval food around settlement.


Now the detailed stuff:

For a very simple larval rearing tank, take a container, put saltwater in it, add an airstone/gentle sponge filter, and - if needed - a heater that is blocked off by a fine mesh (preferably less than 40 microns).

Some larvae may need more than just room-lighting/ambient lighting too,

For an example of a simple larval rearing setup:

Breeding Palaemon Elegans (Mediterrane Rock Pool Shrimp) Guide

Hi, Im going to post a breeding guide of palaemon elegans shrimps here. Two females are preparing for spawning so if you are interested you may want to stick with me. This breeding guide will be interchangable for every kind of shrimps but i stick elegans because: - With cleaner shrimp we are...

www.reef2reef.com

-You need larval food cultures; in this case, that means small copepods like Parvocalanus crassirostris or similar.

-You need some small sieves/screens (like 45-50 microns or so) to feed only the tiniest pods at first, and you'll need to move up sizes to allow bigger pods as the fish grow. Eventually, you can transition them to larger foods like BBS and/or small pellets (like TDO Chromaboost or Otohime pellets).

It's definitely work to do, but attempting (succeeding can be a different story) to rear the larvae isn't too complicated if you can maintain the feed cultures (pods/rots/BBS and phyto).

(I really need to get around to organizing this info one of these days.)

"Some general advice that might help:
- Have a tank ready to move the larvae into (basically a tank with an air stone, a dim light, and a heater - a kreisel tank is ideal, but not necessary; you don't want a filter, a skimmer, uncovered pumps/powerheads, etc. - it needs to be as pelagic larvae safe as possible).
- Be prepared to catch the young when they hatch (ideally, you'd be able to move the eggs immediately before hatching into the new tank, but I'm assuming you don't know exactly when they'll hatch) - catch them and move them into the larval rearing tank as soon as possible.

Assuming you have fertile eggs, the advice I would give is this:
- if possible, get some Parvocalanus crassirostris pods too (rotifers are great, and I would expect the larvae to go for them, but some fish larvae are picky and prefer pods over rotifers - having both seems like a good way to ensure you have good, small foods for them, and Antennarius pictus was cultured using Parvocalanus nauplii, so it seems likely to be a good food source for them). Artemia and other larger pod species would likely be good to have on hand too for the larvae as they grow.

- Get various sizes of very fine sieves so you can control the size of the feeders being offered to the larvae as/if needed.

- Add phyto directly to the larval rearing tank. It’s a good method of ensuring that the feeders are gut-loaded and healthy, and it makes them easier for the fish to see (better feeding/survival rates are typically observed with this method).
- Observe and note information about the larvae (things like how big the eggs are, how big the larvae are, when the larvae settle, when coloration comes in, etc.) and the larval behaviors (stuff like if they are attracted to light, how they react to light, if they are attracted to certain colors, what feeders they eat and what what sizes of feeders they eat at what days post hatch, what kind of substrate they prefer to settle on, are they cannibalistic, etc.).

- Watch for developmental bottlenecks and issues with your rearing methods.

- A lot of people run into feeder issues their first few times breeding, so I’d have a backup plan in place to be able to get some feeders quickly if you find yourself needing some.

With regards to the sieves and feeder sizes:
- You may need to screen the feed initially to only offer Parvocalanus nauplii.
- Observing the larvae eating when/if possible is important for telling if they are accepting/able to eat the food you are offering them.

And to explain the sieving/screening of nauplii to feed:

Yeah, you'd need to screen the Parvocalanus culture prior to feeding them so that you're only offering the baby Parvocalanus pods (the 1st stage nauplii) to the fish larvae. This is what I was meaning when I brought up sieving the culture if the feeders were too large.

Adult Parvocalanus pods get up to 400 microns, whereas stage 1nauplii are about 40 microns. This means that they should be ~1/10 the size of the adult pods (which looks like it would fit with the ~20% gape rule). So, basically, before offering the feeders to the fish, strain them through a 45 or 50 micron mesh - this ensures that you're only getting the smallest available feeders (those that are small enough to fall through a 45 or 50 micron mesh), which should be more appropriately sized for the larval fish.

Generally the main thing to watch for at this stage is a bottleneck where the young start dying off - these usually happen after a few days (day three post hatch seems to be one of the most common bottleneck days for fish that hatch with a yolk they can feed off of - if the rots and phyto don’t provide the proper nutrition for these guys, you might see a die off sometime around here). Some fish run into multiple bottlenecks, including some that happen around/after 2-3 weeks post hatch, so you really need to keep an eye on how things are going. Bottlenecks typically occur because the food the fry is eating isn’t nutritious enough for them, or they’re not interested in eating the food offered, or the food isn’t the proper size for them to eat.

if you do run into a bottleneck and lose this batch, don’t get too disappointed by it - this happens frequently in trying to breed a new species (even to the professionals), and every attempt gets one step closer to success.

With regards to the substrate settlement:
- Some species need sand, rock, dark areas, specific colors, or other oddly specific things to settle on/in (from what I've seen, inverts are usually a lot more picky with this), so it may help to have a ledge or cave (PVC should be fine for this, if it's even needed, which I honestly kind of doubt) and a little sand in the larval rearing tank.


That’s all I can think of at the moment - hope it helps!"

This last link gives a bunch of info on rearing difficult species and trying to troubleshoot problems with the rearing:

Has anyone successfully raised Sunshine Chromis from fry?

Hey all, So I have a breeding pair of sunshine chromis in my reef tank. They have laid 3 batches of eggs that I’ve seen so far, and by the third day, all the eggs are gone (I’m guessing the snails knock them off or my purple tang eats them). I managed to collect and hatch a handful from the...

www.reef2reef.com

As an important note, Midas Blenny larvae seem to hit a bottleneck ~2 days after hatching, so if you see a mass mortality around then despite feeding properly sized Parvocalanus pods, that's probably a good indicator that they're either not feeding on the pods, or not getting proper nutrition from the pods - while it would be disheartening, this would be fantastic information to share and try and build off of.


Good luck, and please keep us updated on how it goes!

 

[F i s h y]

Welcome to Reef2Reef!

Midas Blennies (Escenius midas) are likely going to be a tough one to figure out how to raise, but I think we can figure out a few things to at least get the community started here.

If the eggs are laid on the PVC pipe, then the easiest way to collect them would be by waiting until shortly before they should hatch on the night they're going to hatch (may vary a bit with temperature, but it should be after lights out ~5 days after laying from what I can find), then swapping out the PVC in the broodstock tank for another piece that looks the same while moving the eggs to a larval rearing tank.

These guys should lay eggs pretty regularly (with only a few days between each spawn, from what I can find), so if you don't succeed with this first batch, you should have plenty of chances to try again (and the more info you can get and share here, the better).

Phyto isn't really used for feeding the fish larvae themselves - it's more used to feed things like copepods, rotifers, and Artemia (Brine Shrimp) which in turn are used to feed the fish larvae.

With Midas Blennies, I know that L-Strain Rotifers have been tried without success, and with other blennies of the same genus (E. bicolor and E. gravieri), I've heard of S-Strain Rotifers and Apocyclops panamensis copepods being used unsuccessfully as well. Given that the larvae are way too small for Artemia nauplii and that the only species in the genus which I can find has confirmedly been reared so far is E. gravieri (reared by ORA), I'd guess it's safe to assume these need either difficult feeders, or feeders not generally available to hobbyists.

So, a good place to start would be with Parvocalanus crassirostris (cultured with/fed Isochrysis galbana/T-Iso), and if that doesn't work there are a few more that can be tried (like Oithona colcarva), but they're a lot more work to get a culture of because they're not sold as individual cultures to the public.

Here's my advice for this - a quick summary, then the more detailed stuff:

-Setup a little, simple tank.
(The larval rearing tank).

-Add the larvae.

-Add the larval food and enough phytoplankton to tint the water green.
(The phytoplankton helps dim the lighting so it's not too bright for sensitive larvae, it makes it easier for the larvae to see the feeders, and it gutloads the feeders so they're more nutritious when eaten).

-Adjust feeding as needed as the larvae grow; you typically should start feeding regular fish food in addition to the larval food around settlement.


Now the detailed stuff:












As an important note, Midas Blenny larvae seem to hit a bottleneck ~2 days after hatching, so if you see a mass mortality around then despite feeding properly sized Parvocalanus pods, that's probably a good indicator that they're either not feeding on the pods, or not getting proper nutrition from the pods - while it would be disheartening, this would be fantastic information to share and try and build off of.


Good luck, and please keep us updated on how it goes!

This may be one of the best responses i have ever read on this forum... Well done... Well done.

 

[MidasBlennyGuy]

Thank you @ISpeakForTheSeas! You definitely gave a very detailed yet understandable explanation. To give you an update, I keep my salenity ever so slightly below what labs have done with others from the same genus and my water temps have stayed around 75.3 at night and 76.7 during the day. I had my first nest hatch tonight and it appears at a quick glance to be an 85% fertilization rate. They are darting to the surface so I added three different kinds of phytos that i'm culturing in hopes one will be the right size and be attractive for the larvae. After I posted this thread I had my second nest in the tank laid maybe 24 hours later and this Saturday I found another fresh nest. This first hatch I'm going to scratch it off as a loss for collection and just try to photograph the post-hatch daily progression as they die off. I will most likely relocate the second nest tomorrow in hopes I can catch all the larvae in one tank. I will look into finding someone who may have the E. gravieri through some connections with labs that I know. Thanks again so much and I'll keep y'all posted

 

[ISpeakForTheSeas]

They are darting to the surface so I added three different kinds of phytos that i'm culturing in hopes one will be the right size and be attractive for the larvae.

Just a reminder - the phyto doesn't feed or attract the larvae; the copepods and such do.

The larvae eat the copepods, and the copepods eat the phytoplankton.

 

[MidasBlennyGuy]

I understand that all larvae tend to feed on copepods (not phyto) when their mouths develop, however... I took one larvae from the 24hrs post hatch and the stomach was green which indicates whatever it ate contained the Tetraselmis chui strain of Phytoplankton I had dosed in the tank since I did not have rotifers on hand at the time. Would this suggest I have rotifers in my system already? Refer to the picture attached below.

 

[ISpeakForTheSeas]

I understand that all larvae tend to feed on copepods (not phyto) when their mouths develop, however... I took one larvae from the 24hrs post hatch and the stomach was green which indicates whatever it ate contained the Tetraselmis chui strain of Phytoplankton I had dosed in the tank since I did not have rotifers on hand at the time. Would this suggest I have rotifers in my system already? Refer to the picture attached below.

It's possible that you have some kind of "pod" (copepod, rotifer, etc.) in the tank that they fed on, yes (copepods, at least, are actually incredibly common hitchhikers) - it's also possible that the larvae are unintentionally ingesting the phyto by itself.

Regardless, even if they're feeding on something in the tank, that thing won't be found in high enough quantities to rear the young even if it meets all the criteria to do so.

To rear larval marine fish, you need (at least approximately) the right number/density of feeders (pods) of the right size that move in the right way to entice the larvae to feed and that are of the right nutritional makeup to meet the larvae's needs.

The phytoplankton - while useful in a variety of ways - is not enough to rear the larvae. They need pods of some variety to feed on - the trick is often figuring out which variety and how many of them.

Again, rotifers have been tried with larvae of this genus without success, so rotifers are extremely unlikely to meet the needs of this species. Copepods are your best bet at this point.

 

[MidasBlennyGuy]

I believe I may have found a solution for the feeding issue thanks to @ISpeakForTheSeas words of advice and wisdom. I noticed that reef nutrition makes "Roti-feast" and the size ranges from 40 to 275 microns. I have been dosing feed every three hours for the past 24 hours. All the larvae appear to be eating it since the second the food gets in the water and the cloud drifts past, they swim in and appear to target and eat the food. Would that food be of suitable size and nutrition for the developing larvae?

 

[ISpeakForTheSeas]

I believe I may have found a solution for the feeding issue thanks to @ISpeakForTheSeas words of advice and wisdom. I noticed that reef nutrition makes "Roti-feast" and the size ranges from 40 to 275 microns. I have been dosing feed every three hours for the past 24 hours. All the larvae appear to be eating it since the second the food gets in the water and the cloud drifts past, they swim in and appear to target and eat the food. Would that food be of suitable size and nutrition for the developing larvae?

The pieces closer to 40 microns would be appropriately sized, yes.

However, since Roti-Feast is made of L-Strain Rotifers which have been tried unsuccessfully before and are a staple of the aquaculture community (so they likely have been tried many times before), I expect it will be nutritionally insufficient for the larvae, and that you'll see a mass mortality event even if they're eating it.

That said, it's interesting that they seem to be eating it, as most larvae need very specific movements from their foods to entice them to eat; hence why live food is pretty much always necessary.

Which batch/batches are you feeding?How have the individual hatched batches faired so far? Any surviving larvae from the first or second batch?