Thursday, February 20, 2014

Kryptolebias marmoratus - The Mangrove Killifish

Kryptolebias marmoratus was first described as Rivulus marmoratus in 1880 by Poey, and later as K. marmoratus by Costa. It is a new world fish that inhabits mangrove swamps and estuaries from coastal Florida through Central America to Brazil and the Caribbean Islands.  Due to the nature of these habitats, it is highly adaptable and can live and breed in water conditions ranging from fresh water to hypersaline. 

Unless you like brownish-grey fish, K. marmoratus is not an attractive fish.  Some people would consider it downright ugly.  It makes up for that by being interesting, for a number of reasons.  Recently scientists have found that it can spend a great deal of time out of water, up to 66 consecutive days.  It spends its time in leaf litter, rotting logs, and mud burrows formed by insects or crabs.  It was considered rare in much of its US habitat as it wasn't being found in great numbers.  Until researches found them by the hundreds in rotting logs.  In the aquarium, if your tank is not full and you have something floating on the surface, you'll likely be able to sneak up on them out of the water.  Mine spends time on the cork for a spawning mop, and occasionally sticking to the aquarium glass. 

K. marmoratus is most famous for being one of only 2 known self fertile hermaphrodite vertebrates.  The other is the closely related K. ocellatus.  This means that one fish is generally a breeding "pair" and while sexual reproduction takes place, offspring are basically clones of the parent.  Males do exist and will sometimes form in aquarium populations.  Formation of males can happen for a number of reasons, but typically they form in response to environmental conditions.  One way to trigger them is to raise the fish in saline or hypersaline conditions.  Males are somewhat more attractive than females, having some yellow in the fins and a light covering of blue iridescence.

I found Kryptolebias marmoratus fairly easy to spawn and raise in a typical mop-spawning killifish type setup.  I use a 2.5 gallon aquarium with a sponge filter, spawning mop, and a tight fitting lid.  Remember that they're found out of water?  They travel by jumping.  A lid with only a hole big enough for an airline is important, otherwise they WILL find their way out. 

As stated, this fish is adaptable to a wide range of water conditions, but water should be fairly hard.  My water is relatively hard out of the tap, and I add some reef salt for this fish.  I typically don't measure it out, just grabbing a clump from the bag, but I usually estimate about a tablespoon.  I perform 80% water changes every week.  Temperature can range from 70 to low 80s for this fish, mine have been breeding fine at 70-72.

K. marmoratus isn't terribly picky about food, but it does need more than just flake food.  Mine gets frozen bloodworms, frozen Mysis, live fruit flies, and live redworms regularly.  This is occasionally supplemented with repashy and flake.  They have a large appetite and can eat quite a lot of food.

Breeding this fish isn't terribly difficult.  You have an advantage of having to please only 1 fish here, no incompatible breeding pairs!  They lay eggs in plant matter, gravel, or in my case a spawning mop.  In the mop eggs are usually found near the top, as tight to the cork as the fish can get them.  I pick eggs daily and place them in a dish with chlorinated water, I change water on the eggs every day until I see development.  This cuts down on the number of fungused eggs, which I remove as they appear.  Eggs hatch in 14-21 days and fry are able to eat newly hatched brine shrimp immediately. 

As the eggs hatch, I transfer the fry to a 2.5 gallon aquarium, half filled with aged water and a clump of java moss or najas.  I feed baby brine and microworms daily.  After the first week I raise the water level a little every day until the tank is full.  At the end of week three I start doing 25% water changes.  After the fry surpass the 1/4" mark, these water changes are increased in quantity to 80% per week.  Fry growth is moderate and juvenile fish should start laying fertile eggs in 6 months or so.

Tuesday, January 7, 2014

MAS Fish-O-Ramma - 1/12/14

Looks like I'll be bringing some things along to the MAS Swap. Here's a list of what I might bring, all are limited to 1 or 2 groups & some I'm not decided on yet, so if you're interested in something send me a message.

Ameca splendens

Xiphophorus xiphidium Rio Purificacion
Lyretail swords, brick red - short-fin males are albino geno
Girardinus metallicus (possibly all females, 1 is a possible male)
Characodon lateralis Los Berros
Black Moscow Guppies
Endlers
Apisto cf alacrina F1
Sciaenochromis fryeri Albino 1m/3f group
Xystichromis phytophagus breeding group
Male Pseudotropheus saulosi
Male Gephyrochromis lawsi
Cherry Shrimp

Live Foods:
Microworms
Wingless Fruit Flies
Redworms

I also have a 55 gal tank, tops, & stand. $125 OBO pre-pay via paypal only... I'm not dragging it along if it's not paid for. Very clean, water tested in November and will test again before selling. Pics available.

Thursday, February 21, 2013

Nothobranchius sp. Caprivi Strip

Nothobranchius sp. Caprivi is an undescribed species from Namibia, specifically from the Caprivi Strip which is a tract of land that separates Angola and Zambia from Botswana.  They were originally discovered in the Chobe River floodplain by Van der Waal during investigations carried out between 1973 and 1977.  It was found in only 3 of 39 locations sampled. 

To my knowledge the first importation of this fish was in 1995 when it was collected by Watters, Wood, and Ipple.  These fish were found at the Gunkwe locality, one of the original collection sites.  They were collected again in 2000 or 2001, but this location did not become widely distributed in the hobby.  It was collected once more in 2007 from a location called Salambala.

N. sp. Caprivi is very similar to but distinct from blue forms of N. kafuensis.  The body is nearly solid iridescent blue, with irregular red vertical bars.  The dorsal fin is heavily marked with red, the anal and caudal fins feature black marginal bands with blue and red submarginal bands.  Females are a light silvery-grey and may have some fine dark markings on the body.

One or two pairs of this species can be kept in a 5 gallon aquarium.  I prefer large breeding groups whenever possible and keep a number of fish in a 20 gallon tank. Males spar and display, but damage is rarely done.

Water changes of 50-80% are carried out every week.  Salt is added at a rate of 1 tablespoon per 5 gallons of water, as this is one species that velvet has been a problem with in my fishroom. 

Adults are fed a variety of foods including blackworms, frozen bloodworms, grindal worms, frozen shrimp, and flakes.  They are not picky eaters and have good appetites. 

Breeding is carried out in typical fashion.  If they adults are well fed and the water is clean, they will spawn.  I personally use plastic container of some sort with peat or coir.  I don’t have a problem with the container floating, and don’t weight them down.  They are a prolific spawner, and eggs can be collected weekly.  Incubation temperature should be in the mid 70s.  The 95-1 strain often hatched in 3-4 months, but the newer Salambala strain seems to have a longer hatching window.  I often hatch a small number of fry at 3 months, and then a large number hatch at 7 months. 

Fry are somewhat small, but can eat newly hatched brine shrimp.  I also feed microworms when I have them as well as golden pearls and decapsulated brine shrimp eggs.  As they grow they also get grindal worms and flake food.

Fry growth is quite fast and first signs of sexing out can be seen at 6 weeks.  Males often grow faster than females, so separating the fry as they grow can be beneficial.  Another reason for separating the fry by size is often I’ll get a few dominant males that will slow the growth of other males.  Eventually as the fry mature they all reach a similar size and I put them back into one tank. 

 Nothobranchis sp. Caprivi is a beautiful, prolific, and relatively easy species to keep.  It’s a good next step after keeping some of the easier species with shorter incubation times. 
 

Background

Nothobranchius furzeri is an annual killifish found in Mozambique and Zimbabwe. It occurs in small freshwater pools south of the Save River and north of the Incomati River, and inhabits basins of the Limpopo, Changane, Chefu, Mazimechopes and Vaneteze rivers. It is commonly found with N. rachovii and N. orthonotus. North of the Save River, N. furzeri is replaced by the recently described N. kadleci.
N. furzeri is a fairly robust species, growing to 3”. The body color is generally light turquois with a red reticulation, although solid red strains exist. The anal fin is red, and the caudal has a black margin with a red or yellow sub-marginal band depending on locality.
It is often stated to be the shortest-lived vertebrate species with a life span of 12 weeks in nature. However a 2005 paper by Michael LePage found the coral reef pygmy goby Eviota sigillata lives only 8 weeks. In the aquarium, N. furzeri can live up to 6-8 months, but shows signs of decline around 5 months.
Aquarium Care
Like most species of Nothobranchius, N.furzeri will tolerate a range of conditions with a preference for neutral to moderately alkaline water

with a temperature range of 75-78 F. Salt may be added to the water at a rate of 1 tbsp per 5 gallons up to 1 tsp per gallon. I generally find this unnecessary as long as the tank is kept clean. I change 50% of their water every 10 days and haven’t had problems with velvet.
Keeping N. furzeri does pose some challenges compared to other species of Nothobranchius. I’ve found to be most successful with them I need to keep them in a larger than typical aquarium. I keep most of my nothos in groups in a 20 gal long. N. furzeri is kept in a 33 gal. Both sexes can be aggressive. If they are raised together in a group, they seem to do well. But if they are separated for a short time, they must be kept separate and supervised during spawning. They also eat quite a bit more than other species. I feed them live black worms, frozen bloodworms, and chopped red worms and cocktail shrimp. Ideally they should be fed multiple times per day. Feeding has been the biggest challenge with keeping this fish for me.
Breeding and Raising Fry
N. furzeri is a prolific breeder and getting them to spawn doesn’t present any difficulties as long as they are well fed and have clean water. Peat and Coir both work well as a spawning media, I use a fairly large amount in a margarine tub. They can be messy spawners and using a dish with a hole cut in the cover may help.
 
Incubation typically takes 5-7 months. I’ve hatched large numbers of fry as early as 2 months so it pays to check the eggs monthly. I typically will hatch fry in a large margarine tub, which I will lower into a ½ filled 5 or 10 gallon tank depending on how many fry have hatched. Fry can take newly hatched brine shrimp nauplii on hatching. The fry tank is filled daily until full after the first week. After that I do 80% water changes weekly. They grow very quickly, showing signs of sexual maturity at only 4 weeks. For me, females initially grow more quickly than males, which catch up and surpass the females in size.
Nothobranchius furzeri has become one of my favorite killies. It’s somewhat challenging, but not so difficult it can’t be maintained long-term. With a little extra care and attention, they can be easily kept and are very rewarding.

Golden Pearls - An Excellent Fry Food


I’ve been using an excellent dry fry food for very small fry called Golden Pearls since 2004. I use the 50-100 micron size, as a comparison Artemia nauplii are around 400 microns. It’s been great for tetras, bettas, danios, rainbows and of course killies. It worked great for small killi fry like E. annulatus and N. janpapi. I also feed it to larger fry. A little goes a long way. I bought ½ lb in 2004 from Brine Shrimp Direct and have just gotten through the first ¼ lb package. Keep what you aren't using in the freezer to extend it's shelf life.

Here’s the description from the BSD website:

"Golden Pearls is a revolutionary new larval diet that has successfully replaced live Artemia nauplii in marine fish hatcheries in Europe. A patented processing technique (agglomeration of micro-encapsulated particles) results in feed particles or "clusters" that resemble raspberries under the microscope. Golden Pearls have tiny air pockets that keep the feed particles in the water column, not on the bottom of the tank. Golden Pearls mimic live brine shrimp nauplii."

Available in Seven particle Sizes

· Diatom Replacement: 5-50 microns

· Diatom Replacement: 50-100 microns

· SS Rotifer Replacement: 100-200 microns

· LS Rotifer Replacement: 200-300 microns

· Artemia Nauplii Replacement: 300-500 microns

· Instar V Replacement: 500-800 microns

· Baby Brine Replacement: 800-1,000 microns

Nothobranchius boklundi Luangwa Valley ZAM 09-2



Nothobranchius boklundi is a relatively new species of annual killifish from Zambia discovered by Jorn Boklund in 2009 in the Luangwa river valley.  It is part of the N. brieni species group and is similar to N. kafuensis.  It is differentiated from N. kafuensis by coloration and morphological characteristics. 

N. boklundi has an overall blue iridescence to the body and red reticulation with a blue or orange-red caudal margined in black.  The dorsal and anal fins are heavily spotted with red and may be yellow to red with some blue iridescence and no marginal bands. 

I obtained eggs from Bob Morenski in the summer of 2010, and a small number were ready to hatch in late October.  The fry are large enough to eat newly hatched brine shrimp and microworms.  Raising the fry posed no unusual problems, although I did have some mortality.  In N. kafuensis males often grow much more rapidly than females.  I did not have that problem with N. boklundi, and both sexes grow at about the same pace.

I usually breed in groups in a 20 gallon long tank.  They’ve turned out to be quite prolific and not aggressive at all.  Their diet is the same as it is for most of my fish: BBS, frozen bloodworms, live white worms, live blackworms, chopped redworms, daphnia, grindal worms, and dried foods.  I perform 50-80% water changes every week.  

Every two weeks I change the spawning medium.  Currently I’m using coir (ground up coconut husks) and I like it better than peat so far.  Incubation takes 4-9 months, but it’s important to watch the development of eggs from all species.  It’s the only way to be certain they’re ready to hatch.  After hatching I transfer the fry to a ½ filled 2.5 gallon tank.  I re-dry the medium, check for eggs, and re-bag and store the eggs for another month or two. 

I routinely get fairly large hatches of fry.  I have never seen a red form of the species other than in pictures, and have heard the same thing from everyone I've talked to who breeds this species.  If you are getting males with red caudal fins, please let me know!  I'd love to get that diversity in my strain.

Thursday, February 14, 2013

Elassoma zonatum - The Banded Pygmy Sunfish


Banded pygmy sunfish, Elassoma zonatum, are a small freshwater fish found in North America.  They range from North Carolina to Florida west to Texas and north to Indiana and Illinois.  Like most Elassoma species, they inhabit swampy slow moving waters with plenty of aquatic vegetation.  Not true sunfish, they’re in their own family, Elassomatidae, with the other species of Elassoma.

E. zonatum is probably the least colorful species in the genus, but they are still attractive despite their drab coloration.  Both sexes are grey to tan and have vertical bars on their bodies.  Males tend to be darker, have more pronounced bands, and have dark fins whereas the female has relatively clear fins.  My females are slightly larger and more robust looking.  Males can get some very subdued blue iridescence, but you really have to look for it to find it.    

My fish are from Texas and were collected by Brian Perkins of WildPERU.  I received a group of 6 in late December and set them up in a 5 gallon tank with a huge clump of java moss.  I lost 2 in the first week, but they settled in well and turned out to be 1 male and 3 females.  Water was kept about 225 ppm hardness and 75°F.  They hide quite a bit, but not so much as to be hard to find.  They come out readily for food or to explore the tank but spend their resting time in hiding.  E. zonatum tends to stay near the bottom of the tank, but will explore mid water to find food. 

So far they don’t seem inclined to take flakes or granules.  They will pick at Repashay foods a bit.  I feed them mostly frozen bloodworms, frozen tubifex, blackworms, white worms, grindal worms, and baby brine shrimp.  They have good appetites and will eat quite a bit. 

I wasn’t 100% sure I had any males in early January, so I slowly lifted the moss out to find the adults.  My curiosity was answered by the very large number of miniscule fry dropping out of the moss as I lifted it through the water.  I didn’t need to ask Brian to bring any males to the January meeting; I obviously had males and females.  At this point I moved the adults to a 2.5 gallon tank with a spawning mop for cover while I cleaned out and set up a 20 gallon to house them permanently. 

Fry are very small, maybe only slightly larger than tetra fry.  I’m pretty sure I found them newly hatched, I didn’t come across any free-swimming fry for another week.  I started feeding them on 50-100 micron Golden Pearls and microworms.  After about a week I started them on baby brine shrimp.  For such small fry, they grow fairly quickly.  Once they got to be about 1/8” I started doing 80% water changes every week using aged tap water.  Most fry are growing at a fairly constant rate, but there is a small number that are absolutely huge.  Most are about ¼”, but a few are ½” or a little bigger.  I’m not sure why this is.  I’m not sure that it’s a simple matter of males growing faster, as that’s a much bigger difference than I normally experience with other species.  

Good tank mates would be other small fishes that inhabit the upper regions of the aquarium.  I’m now keeping them with Epiplatys annulatus, the clown killifish.  It seems to work well as the killies stay at the surface and the sunfish stay near the bottom.  A small mid-water schooling fish would be an excellent addition too.  While a little picky about what they will eat, Elassoma zonatum have been overall easy to keep and would make excellent candidates for nano tanks or planted setups.