Saturday, June 22, 2019

What Is the Life Cycle of a Cherry Shrimp?

Ever wonder how long it takes for baby cherry shrimp to hatch? Or how the female’s eggs get fertilized? Keep reading to learn about the amazing life cycle of a cherry shrimp!

When I started keeping shrimp, everyone online just said, “Oh, throw some together and you’ll have hundreds in no time!” Yeah, but how long is that supposed to take? I delved deeper into the freshwater shrimp community, and I found very few resources describing how cherry shrimp breed. I mean, if I don’t know exactly how they reproduce, how do I know if I’m doing something wrong? So today I’m going to tell you the story of a little girl shrimp and a little boy shrimp and how they make babies.

How to Sex Shrimp and Determine if They're Male or Female

Okay, let’s start with adults and how to sex them. If you have 10 shrimp, there’s like a 99.8% chance you’ll have at least 1 male and 1 female, so start with at least 10-20 shrimp to ensure you have enough viable breeding pairs. Now this may vary a little between the different color morphs of Neocaridina davidi, but at least for red cherry shrimp:
  • Female: 
    • Larger in size, about 1” or 2.5 cm
    • Redder, darker, or more solid in coloration
    • May have a white or yellow saddle on their back (which are undeveloped eggs in the ovaries right behind the head of the shrimp
    • May be carrying eggs under their tail
    • Often has a curved, rounder underbelly (especially if they've been pregnant before)
  • Male: 
    • Smaller, about 2/3"-3/4” or 2 cm
    • Almost transparent in color with red markings
    • Tail is thinner (similar to a juvenile's tail)
    • Difficult to see, but has special reproductive structures on the first two pairs of swimmerets

male vs. female cherry shrimp

How do Cherry Shrimp Reproduce?

So if you have shrimp of opposite genders, stable water conditions, and plenty of yummy food, the female will develop eggs in her “saddle” where her ovaries are located. Once the eggs ripen, the female will molt her exoskeleton, which looks like a clearish-white shrimp shell that’s completely empty inside. Her new exoskeleton will be soft and flexible, which makes fertilization with the male possible. (Pro tip: make sure your shrimp have plenty of nutrients and minerals to successfully molt if you want to see babies.)

After the female molts, she’s feeling pretty vulnerable with her new soft shell, so to avoid being eaten, she goes into hiding and then releases pheromones or a chemical signal into the water as a signal to the males that she’s ready do the funky monkey dance. So if you see a ton of male shrimp frantically swimming around the tank, instead of passively grazing for food, you know that they’re looking for that newly molted female. And if you see a couple of shrimp that look like they’re “fighting” but there’s no food around, it might be a breeding pair gettin' busy. (Pro tip: make sure not to cull too many males or they’ll have a hard time catching the female right after her molt.)

Shrimp sex is very fast and supposedly occurs less than 10 seconds. The male latches onto the female such that they're facing one another other, deposits his sperm in the female’s genital opening, and then quickly releases her. At this point, the female’s eggs will pass through the deposited sperm as they travel from the ovaries inside her to the outside of her body under her tail. Therefore if you see a female that is “berried,” or holding eggs under her abdomen, then the eggs are definitely fertilized.

mating Neocaridina davidi
Mating red cherry shrimp (source: Peter Maguire)

How Long do Cherry Shrimp Eggs Take to Hatch?

Fertilized shrimp eggs rather large (about 1 mm in diameter) and look yellow or green in color. A transparent, ribbon-like membrane binds the eggs to the female’s swimmerets, and she uses the rear ones to fan the eggs, clean off any bacteria or fungus, and increase oxygen flow. Depending on the temperature of the water, the eggs may hatch anywhere from 15 to 35 days. Other sources say 2 to 3 weeks, so that’s a pretty wide range. The closer the eggs get to maturity, you may notice little black dots in the eggs, which are the baby shrimps’ eyes.

female berried shrimp - Neocaridina davidi

What do Baby Cherry Shrimp Look Like?

When they’re ready to come out, the mom will help the baby by kicking at the egg, so it almost looks like the hatchling flies out like popcorn. Unlike other types of shrimp, Neocaridina shrimp lack a larval stage, so the babies look like itty-bitty, clear versions of the adult shrimp, about 2 mm in length and less than 1 mm in height.

The hatchlings aren’t very mobile at this point since their swimming appendages don’t work properly yet, so they’ll basically latch on to the first thing they find and then try to hide among the rocks and plants as they graze on biofilm. (Pro tip: consider adding plenty of hiding spots and feeding a powdered baby shrimp food to supplement the biofilm.) So don’t worry if your female suddenly “loses” her eggs; most likely the babies are just hiding for the first 3-4 days.

newly hatched red cherry shrimp

How Many Babies Can Each Female Shrimp Make?

Each berried female usually produces about 21-51 babies per batch, supposedly on the higher side if the female is larger, probably because she can produce and hold more eggs.

How Long Does It Take for Cherry Shrimp to Reach Sexual Maturity?

I’ve heard anywhere from 2.5 months (when scientists kept them at 80°F or 27°C), all the way to four to six months. As I mentioned before, the female will be a little less than 1” in length (2.3 cm) and the male will be maybe two-thirds to three-quarters of an inch (a little less than 2 cm).

What is the Life Span of Cherry Shrimp?

In general, the expected total lifespan of cherry shrimp is 1-2 years. I’ve noticed that my oldest, largest females do not tend to carry eggs very often compared to my younger, smaller females. (Pro tip: don’t buy the biggest shrimp you see because they may be too old to breed.)

If you really want to up your shrimp breeding game, check out my other shrimp breeding tutorials. Take time to enjoy your aquariums and I’ll see you in the next post!

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