Yes they are. Do you have any snails? They look like shrimp eggs that were dropped. The females have to learn how to hold them properly in their pleopods (under their tails), and they usually drop most or all of their first clutch before they figure it out. If you don’t have any snails and they’re definitely shrimp eggs, you could collect them and put them in a container of clean tank water with an air stone or hang them in a fine mesh net under your filter outtake and they may hatch – they need to be oxygenated, so unless you replicate the way the mother fans them in her pleopods they won’t hatch. But that’s really fine, because if they’ve already started mating in just three weeks that means they’re happy and comfortable with your water, so they’ll probably be berried again sooner than you’d think. Once they start they don’t stop. Shrimp you buy at pet stores etc. are usually young, so it’s probably their first attempt at babies. They’ll figure it out. Keep an eye on the females’ backs where the tail meets the head and you’ll see a yellow “saddle” form (it literally is the shape of an English saddle) – that’s when she’s forming the eggs. Then she’ll molt, mate with a male, lay the eggs, and hold them under her tail until they hatch. The eggs can be any color from pale yellow to bright green, and you’ll definitely notice them right away – when my young girls have their first clutches, there’s usually eggs hanging out in all directions. As she learns how to care for the eggs, she’ll start keeping future clutches tightly tucked up under her tail, and you’ll notice her tail getting wider as she grows. The shrimplets are TINY and clear so you might not be able to find any for awhile after they hatch, unless you’re the type to spend hours staring into your tank (I am). They will hide in the gravel and moss until they’re a little bigger.
As for the algae, shrimp do graze on most types of algae but they don’t eat enough to keep your glass clean. Algae is most often caused by too much light and/or too much food – try cutting back on light first, but also remember that shrimp don’t eat much and you should be removing uneaten food with a net or turkey baster. I learned years ago to shut my lights off for a few hours in the middle of the day to disrupt the algae growth, and it works great – if you don’t have a timer for your light yet, I highly recommend one because they’re cheap, and it’s not easy to turn the lights off and on every day at the same time which is what plants like. If you don’t have any snails yet, you might consider a few nerites – they have pretty shells and are the best algae eaters hands down. I can’t tell how big your tank is, but if it’s over 20 gallons or so you could consider a school of otocinclus catfish – they stay small (like 1.5”) and do nothing but suck algae off the glass all day – but you’d need to get at least 6-8 and preferably more because they are schooling fish and need company of their own species. You’d also want to wait at least a few months until there’s a decent amount of algae and biofilm in the tank and it’s well established, because they don’t tend to eat algae wafers and you don’t want them to starve. But you could have at least a couple nerites, even if it’s a small tank, and they definitely earn their keep. I think they’re the best algae eaters I’ve ever had. Or you can just wipe the glass off with a folded up paper towel and call it a day.
manfredowg 
Yes they are. Do you have any snails? They look like shrimp eggs that were dropped. The females have to learn how to hold them properly in their pleopods (under their tails), and they usually drop most or all of their first clutch before they figure it out. If you don’t have any snails and they’re definitely shrimp eggs, you could collect them and put them in a container of clean tank water with an air stone or hang them in a fine mesh net under your filter outtake and they may hatch – they need to be oxygenated, so unless you replicate the way the mother fans them in her pleopods they won’t hatch. But that’s really fine, because if they’ve already started mating in just three weeks that means they’re happy and comfortable with your water, so they’ll probably be berried again sooner than you’d think. Once they start they don’t stop. Shrimp you buy at pet stores etc. are usually young, so it’s probably their first attempt at babies. They’ll figure it out. Keep an eye on the females’ backs where the tail meets the head and you’ll see a yellow “saddle” form (it literally is the shape of an English saddle) – that’s when she’s forming the eggs. Then she’ll molt, mate with a male, lay the eggs, and hold them under her tail until they hatch. The eggs can be any color from pale yellow to bright green, and you’ll definitely notice them right away – when my young girls have their first clutches, there’s usually eggs hanging out in all directions. As she learns how to care for the eggs, she’ll start keeping future clutches tightly tucked up under her tail, and you’ll notice her tail getting wider as she grows. The shrimplets are TINY and clear so you might not be able to find any for awhile after they hatch, unless you’re the type to spend hours staring into your tank (I am). They will hide in the gravel and moss until they’re a little bigger.
As for the algae, shrimp do graze on most types of algae but they don’t eat enough to keep your glass clean. Algae is most often caused by too much light and/or too much food – try cutting back on light first, but also remember that shrimp don’t eat much and you should be removing uneaten food with a net or turkey baster. I learned years ago to shut my lights off for a few hours in the middle of the day to disrupt the algae growth, and it works great – if you don’t have a timer for your light yet, I highly recommend one because they’re cheap, and it’s not easy to turn the lights off and on every day at the same time which is what plants like. If you don’t have any snails yet, you might consider a few nerites – they have pretty shells and are the best algae eaters hands down. I can’t tell how big your tank is, but if it’s over 20 gallons or so you could consider a school of otocinclus catfish – they stay small (like 1.5”) and do nothing but suck algae off the glass all day – but you’d need to get at least 6-8 and preferably more because they are schooling fish and need company of their own species. You’d also want to wait at least a few months until there’s a decent amount of algae and biofilm in the tank and it’s well established, because they don’t tend to eat algae wafers and you don’t want them to starve. But you could have at least a couple nerites, even if it’s a small tank, and they definitely earn their keep. I think they’re the best algae eaters I’ve ever had. Or you can just wipe the glass off with a folded up paper towel and call it a day.
dropped clutch rip. Heard people of still having them fertilized