Longear Spawn Questions

This system I used for bantam sunfish which are pretty picky, relative to longears, about their brine shrimp during first few days.

Cheapest method I used involved 1 quart jars filled one half full with ~15 ppt salt water (NaCl: no iodine added). Stress approximately 15 ppt. Approximately 0.5 grams of cysts and salt is added along with salt and aged water to jar (arming hatcher). One is armed in AM and other in PM. Extra light, preferably from a flourescent fixture, blasting hatching jars promotes better hatch. Temperature needs to be upper 70's to lower 80's. Temperature very important. Aerate vigerously with small air pump. I like to use glass eye dropper to reduce bubble size. Do not use airstones, bubbles too small and cause cysts to be separated from solution and stuck to jar sides above water where they do not hatch. After 20 to 24 hours remove diffuser and place jar at 45 degree angle in some sort of uneven surface (i used a bowl) and let set for 10 to 15 minutes. Unhatched cysts will sink and hatched cysts will float at surface. Siphon the orange mass of newly hatched brine shrimp using another glass pipet attached to a siphon into another jar. Be carefull not to suck up cysts or shells which means not getting a nauplii. Cysts and shells in with larvae and fry is bad. Gently aerate harvested nauplii until used. Do not reuse brine solution because sets stage for disease. Try to feed out nauplii within 12 hours, shorter is better.

I made all sorts of effort to measure cysts and salt by volume instead of weight. I suggest weighing out batches of salt and cysts ahead of time to reduce arming time.

You gotta be carefull not to overfeed. Ideally, all brine shrimp from one feeding consumed before a follow up is applied. If brine shrimp dying before consumed, then back off the amount and siphon out dead. If 10-gal tank is your larviculture tank, then keep number of fry down to a 25 to 50 individuals. Do not hesitate to feed excess brine shrimp to adults. It is an excellent conditioning feed.

I can't thank you enough for the time and expert advice you provided. I plan to start construction on my hatchery this weekend. I hope to have it ready for the next brood if the current batch can't benefit. It will be nice to be prepared in advance so that I can jump into action. Many thanks! I'll let you know how it turns out.

Please excuse my miss spellings. Intended to say "not all nauplii" will be harvested instead of "not a nauplii".

mdwalt1,
Can you provide pictures of your setup? Will help in treamlining the brine shrimp harvesting.

I was able to piece together some existing items to construct a hatchery. It consists of three 1-quart mason jars, two air pumps, a 2.5 gallon fish bowl, a 3-way gang valve and some air tubing. I have a pump being split three ways into each mason jar using a straight piece of tubing with nothing in the end. One jar will be used for harvesting while another will be in process of being armed. The third will house the newly hatched shrimp that are waiting to be served. The fish bowl will hold the larvae until they can be transfered to a larger grow out tank (10 gal) after going through their 2nd metamorphosis and becoming more established.

The only concerns I have are regarding the amount of air pressure being pumped into the three jars and whether I need some kind of cover for the bowl. The water surface seems to be sufficiently turbulent, but I think it may be a bit weak - I'm not sure. The single pump to the bowl with the use of an air stone has proven adequate. Here is a pic of my setup. Any suggestions are welcome.

Edited by mdwalt1, 04 May 2010 - 04:43 PM.

Lets hybridize what you have with what is in following image.

 bs micro-hatchery components.JPG   50.95KB   1 downloads

Starting on left are pre-loaded containers (centrifuge tubes with lids shown) of cysts and salt. Next are two hatching jars, one AM and one PM. Do not use air diffusers (air stones as shown), they just keep air line in jars for photograph. The third jar is the post-harvest (harvested nauplii) jar. Harvest jar should be supplied with aeration as you depict. The tin contains cysts which should be kept in refrigerator except when pre-loading. Next items are a jar of salt and the meauring scoop that hold roughly 1 gram of cysts.

You fish bowl may not be as condicive to larval fish development as a 10-gallon aquarium which has more surface area. Ideally aeration to larval rearing tank will be minimal.

I recommend having brine shrimp hatchery and larval rearing sytems on separate air pump / gang valve systems.

Can do. I especially like the idea of premeasured cysts/salt containers. Will definitely save time when recharging before leaving for work in the mornings. I can store everything in my "beer fridge" in the garage next to my set up. Thanks again for the tips!