75 Gallon Tank "Pregnant" Danio?

Hello, I've got 35-ish Glofish and Gold Zebra Danios in my 75 gallon tank. Some of them have been getting big bellies and I want to know if they're full of eggs or just a little Chunky. I know they don't get traditionally pregnant, but that's an easy way to describe it. I don't really want them to breed (hence no mop and the Dojo Loaches living with them), so if they're not pregnant, that's fine. I don't have a heater in the tank, but the temp floats around the mid 60s.
The one in the picture is a pretty small Danio, but it's belly is probably the best example of what I mean. Sorry it's blurry, they're darty little things. Thank you for the help!

 

The word you're looking for to describe them is gravid! And indeed, that's about what Zebra Danios look like when heavily gravid. Basically, just carry on as you have been and I doubt you'll see any fry. You need either a ton of cover or you have to separate the eggs from all fish for them to have a chance of hatching.

 

If you think they could be chunky, watch how much you're feeding them. Even though the above poster said they're most likely pregnant, the fact that you think chunky is a possibility tells me that you aren't totally confident in the amount of food you're giving them (perfectly okay. everyone starts there). Fish don't actually have anything to tell them that they are full. If there is food available, they'll eat it. That's obviously not a good thing, as they can eat themselves to death. If you notice some are getting chunky (males show it best since you know they arent pregnant), just withhold feeding for 2ish days. They'll be totally fine without food, and have an opportunity to slim down

Also, your tank temperature is a little too cold for them. They'll live, but they wont be as happy as they can be. Glofish prefer temps between 72-80, and danios like 70-78. You probably want to buy a heater (you can get one for under a $100) and get that temp up. They'll be a lot happier in warmer water, and the heater will keep the temp more consistent. Fish don't like temperature changes. It stresses them out and can even kill them.

 

If you think they could be chunky, watch how much you're feeding them. Even though the above poster said they're most likely pregnant, the fact that you think chunky is a possibility tells me that you aren't totally confident in the amount of food you're giving them (perfectly okay. everyone starts there). Fish don't actually have anything to tell them that they are full. If there is food available, they'll eat it. That's obviously not a good thing, as they can eat themselves to death. If you notice some are getting chunky (males show it best since you know they arent pregnant), just withhold feeding for 2ish days. They'll be totally fine without food, and have an opportunity to slim down

Also, your tank temperature is a little too cold for them. They'll live, but they wont be as happy as they can be. Glofish prefer temps between 72-80, and danios like 70-78. You probably want to buy a heater (you can get one for under a $100) and get that temp up. They'll be a lot happier in warmer water, and the heater will keep the temp more consistent. Fish don't like temperature changes. It stresses them out and can even kill them.

OK, that's good to know about them eating, thanks. I have Dojo Loaches in there with them and the internet says they like it between 68 and 76. I don't want to go too warm as to shorten their lives, but I also want all the fish in there to be comfortable... What about two Eheim Jager 150w heaters set at around 70-72. Will that work for them? Thanks for letting me know, that was a big help!

PS: Not all of the danios are that round and I have been working on how much I feed them. They eat flakes and peck a little on shrimp pellets with the occasionaltreat of bloodworms. I'll keep an eye on their weight and rememberwhat you said about fasting them.

The word you're looking for to describe them is gravid! And indeed, that's about what Zebra Danios look like when heavily gravid. Basically, just carry on as you have been and I doubt you'll see any fry. You need either a ton of cover or you have to separate the eggs from all fish for them to have a chance of hatching.

Cool, I don't mind if the odd fry or two happen to survive by some miracle, but I don't want to be overrun. I had an experience with guppies and their fry that changed me forever, lol.

 

OK, that's good to know about them eating, thanks. I have Dojo Loaches in there with them and the internet says they like it between 68 and 76. I don't want to go too warm as to shorten their lives, but I also want all the fish in there to be comfortable... What about two Eheim Jager 150w heaters set at around 70-72. Will that work for them? Thanks for letting me know, that was a big help!

PS: Not all of the danios are that round and I have been working on how much I feed them. They eat flakes and peck a little on shrimp pellets with the occasionaltreat of bloodworms. I'll keep an eye on their weight and rememberwhat you said about fasting them.

Cool, I don't mind if the odd fry or two happen to survive by some miracle, but I don't want to be overrun. I had an experience with guppies and their fry that changed me forever, lol.

eheim jager is such a good brand. That’s the brand I have. I definitely think the two 150w heaters would be fine. That way if one heater breaks and goes to Max strength, it won’t be strong enough kill everything in your tank. 70-72° Is a lot better. Your fish will be much happier. Careful though when you first start raising the temp. Too much change at once will stress them. I think the rule is like 1° every hour or so, Max 3° in a day. That way it’s a slow acclimation for your fish.

Sounds like you’re feeding them right. My fish love bloodworms too. Heck even I overfeed them every now and then and I’ve been doing this over 10 years. My tetras will get lumpy stomachs and that’s how I know I fed them too much in one feeding. It’s just some people don’t know that they’ll continue eating if you continue feeding, so I try to put that out there when I can.

 

eheim jager is such a good brand. That’s the brand I have. I definitely think the two 150w heaters would be fine. That way if one heater breaks and goes to Max strength, it won’t be strong enough kill everything in your tank. 70-72° Is a lot better. Your fish will be much happier. Careful though when you first start raising the temp. Too much change at once will stress them. I think the rule is like 1° every hour or so, Max 3° in a day. That way it’s a slow acclimation for your fish.

Sounds like you’re feeding them right. My fish love bloodworms too. Heck even I overfeed them every now and then and I’ve been doing this over 10 years. My tetras will get lumpy stomachs and that’s how I know I fed them too much in one feeding. It’s just some people don’t know that they’ll continue eating if you continue feeding, so I try to put that out there when I can.

That's great to know about the heaters as I'm shopping for two for a new 55 gallon. I'll do the slow acclimation. Thanks so much for your help!!!