Breeding of Hydrocynus vittatus in aquarium
- Thread starter giseok jung
- Start date
Been scouring and looking for more info. This is what I have so far:
This website", https://fishkeepingfolks.com/african-tigerfish/, reproduction of African Tigerfish section is nothing short of a joke. And I quote,
"The species is sexually mature at about 5 cm SL and will then spawn year-round in their aquarium. A diet containing live foods such as Artemia nauplii or Daphnia magna for a few weeks will help condition them for breeding. The female lays up to 800 eggs on fine-leaved plants (it’s recommended to use a spawning mop), where they are fertilized by the male.
After some days, when they have absorbed their yolk sac, fry becomes free swimming and can be fed newly hatched brine shrimp. They grow very quickly, reaching around 2cm after only 2 months.
It’s important to keep the water quality high during growth, using a large filter and performing frequent water changes. The tigerfish has been known to jump out of tanks with less than 60 cm of water so care should be taken if you plan on keeping it in an open-topped tank without a lid.
Reasons I have issue with this article are:
1. The length of maturity. Faie enough may have been a typo for 35cm.
2. Spawn year round in an aquarium by whose observations?
3. 800 eggs?? Another paper, I will try to find again, found fecundity in larger females to be as high as 780,000 eggs per female.
THIS PAPER : "I. G. Gaigher (1970) Ecology of the Tiger-Fish (HydrocynusVittatus) in the Incomati River System South Africa, Zoologica Africana, 5:2, 211-227, DOI: 10.1080/00445096.1970.11447393" females must be around 360mm (36cm or 14" give or take).
Emailed a guy I have communicated with in the past about African fish species, who is a research associate at the South African Institute for Aquatic Biodiversity specializing in Taxonomy, distribution and conservation of southern African river fishes, also said he does not know of anyone doing it.
ANOTHER PAPER: "Smit, N., Wepener, V., Vlok, W., Wagenaar, G., & van Vuren, J. (2013, January). Conservation of tigerfish, hydrocynus vittatus, in the kruger national park with the emphasis on establishing the suitability of the water quantity and quality requirements for the olifants and luvuvhu rivers. https://core.ac.uk/download/pdf/54194989.pdf. https://core.ac.uk/download/pdf/54194989.pdf"
Sates the following:
"Female fecundity is extremely high with one large female (650 Forked Length (FL)-700 FL) capable of producing approximately 800 000-1 000 000 eggs (Van Loggerenberg, 1983; Skelton, 2001). Males have high sperm counts which is a distinctive feature of stream spawners (Steyn, 1993), but low sperm motility (Steyn & Van Vuren, 1991). Unfortunately tigerfish are not able to capitalise on their high fertility due to factors such as unsynchronised maturity and uneven sex ratios (Steyn, 1987). These problems drastically reduce the chance of successful spawning and thus fertilisation of the females. Uneven sex ratios have been reported in Lake Kariba by Kenmuir (1972) where the female to male ratio was 1.35:1 in non-breeding seasons and 1:4 in peak seasons. Langerman (1984) reported a female to male ratio of 1:1.8 in the same system. Unsynchronised maturity has been stated in many publications and almost seems to be the norm for this species."
There is other interesting information about breeding habitats in different populations in the paper.
THE MOST PERTINENT PAPER I was able to find is "Steyn, G. J. (1996, December 1). Notes on the induced reproduction and development of the tigerfish,Hydrocynus vittatus (Characidae), embryos and larvae. SpringerLink. Retrieved October 8, 2022, from https://link.springer.com/article/1...ted&code=aafb979d-b139-4a48-b623-ce6440bd469c".
I emailed Steyn asking for access to the paper. While waiting for a reply, I went digging and found a website allowing the paper to be downloaded (DOWNLOAD LINK for the paper).
Interesting paper for those interested that is not a long read but gets a little technical.
I will share anymore info I can find or replies to emails I get. Been an interesting rabbit hole to go down especially since I grew up hunting these fish.
This website", https://fishkeepingfolks.com/african-tigerfish/, reproduction of African Tigerfish section is nothing short of a joke. And I quote,
"The species is sexually mature at about 5 cm SL and will then spawn year-round in their aquarium. A diet containing live foods such as Artemia nauplii or Daphnia magna for a few weeks will help condition them for breeding. The female lays up to 800 eggs on fine-leaved plants (it’s recommended to use a spawning mop), where they are fertilized by the male.
After some days, when they have absorbed their yolk sac, fry becomes free swimming and can be fed newly hatched brine shrimp. They grow very quickly, reaching around 2cm after only 2 months.
It’s important to keep the water quality high during growth, using a large filter and performing frequent water changes. The tigerfish has been known to jump out of tanks with less than 60 cm of water so care should be taken if you plan on keeping it in an open-topped tank without a lid.
Reasons I have issue with this article are:
1. The length of maturity. Faie enough may have been a typo for 35cm.
2. Spawn year round in an aquarium by whose observations?
3. 800 eggs?? Another paper, I will try to find again, found fecundity in larger females to be as high as 780,000 eggs per female.
THIS PAPER : "I. G. Gaigher (1970) Ecology of the Tiger-Fish (HydrocynusVittatus) in the Incomati River System South Africa, Zoologica Africana, 5:2, 211-227, DOI: 10.1080/00445096.1970.11447393" females must be around 360mm (36cm or 14" give or take).
Emailed a guy I have communicated with in the past about African fish species, who is a research associate at the South African Institute for Aquatic Biodiversity specializing in Taxonomy, distribution and conservation of southern African river fishes, also said he does not know of anyone doing it.
ANOTHER PAPER: "Smit, N., Wepener, V., Vlok, W., Wagenaar, G., & van Vuren, J. (2013, January). Conservation of tigerfish, hydrocynus vittatus, in the kruger national park with the emphasis on establishing the suitability of the water quantity and quality requirements for the olifants and luvuvhu rivers. https://core.ac.uk/download/pdf/54194989.pdf. https://core.ac.uk/download/pdf/54194989.pdf"
Sates the following:
"Female fecundity is extremely high with one large female (650 Forked Length (FL)-700 FL) capable of producing approximately 800 000-1 000 000 eggs (Van Loggerenberg, 1983; Skelton, 2001). Males have high sperm counts which is a distinctive feature of stream spawners (Steyn, 1993), but low sperm motility (Steyn & Van Vuren, 1991). Unfortunately tigerfish are not able to capitalise on their high fertility due to factors such as unsynchronised maturity and uneven sex ratios (Steyn, 1987). These problems drastically reduce the chance of successful spawning and thus fertilisation of the females. Uneven sex ratios have been reported in Lake Kariba by Kenmuir (1972) where the female to male ratio was 1.35:1 in non-breeding seasons and 1:4 in peak seasons. Langerman (1984) reported a female to male ratio of 1:1.8 in the same system. Unsynchronised maturity has been stated in many publications and almost seems to be the norm for this species."
There is other interesting information about breeding habitats in different populations in the paper.
THE MOST PERTINENT PAPER I was able to find is "Steyn, G. J. (1996, December 1). Notes on the induced reproduction and development of the tigerfish,Hydrocynus vittatus (Characidae), embryos and larvae. SpringerLink. Retrieved October 8, 2022, from https://link.springer.com/article/1...ted&code=aafb979d-b139-4a48-b623-ce6440bd469c".
I emailed Steyn asking for access to the paper. While waiting for a reply, I went digging and found a website allowing the paper to be downloaded (DOWNLOAD LINK for the paper).
Interesting paper for those interested that is not a long read but gets a little technical.
I will share anymore info I can find or replies to emails I get. Been an interesting rabbit hole to go down especially since I grew up hunting these fish.
A lot of websites are quilty of just repeating the same general information for multiple species of fish; Seriously Fish does this a lot, and the general comments at the end of many sections on there are literally quoted word-for-word, complete paragraphs, on multiple pages devoted to multiple related species. And to be honest, the info is probably equally applicable to those various species.
In the laughable case of the H.vittatus quoted above by
cockroach
, it almost seems as though that website took a section devoted to the breeding of some other, much-more-typical species of much-smaller characin, and just slapped it in there as a filler.
"Excellent! Our work here is done! Let's move on to the next species and start disseminating misinformation about it..."
In the laughable case of the H.vittatus quoted above by
cockroach
, it almost seems as though that website took a section devoted to the breeding of some other, much-more-typical species of much-smaller characin, and just slapped it in there as a filler."Excellent! Our work here is done! Let's move on to the next species and start disseminating misinformation about it..."
The article "Steyn, G. J. (1996, December 1). Notes on the induced reproduction and development of the tigerfish,Hydrocynus vittatus (Characidae), embryos and larvae." is comprehensive enough for anyone to replicate induced spawning. If there is sufficient market demand, most fish hatcheries would be capable.
Mr. Hiroshi (writer of that book) also his H. vittatus lay over 30,000 eggs at once.
This is quite a lot for small fish about 30cm that he used for breeding project.
So does this mean that the fish are maintained in larger accommodations, and when they are properly conditioned and "triggered" they are moved to the small tank for the actual spawning? Much like we do for many smaller species, in an effort to control where they eggs are laid and then remove the adults immediately after spawning?
It's easy to forget that true experts, in any field, can "get away" with things that more casual hobbyists like most of us either would not be successful attempting...or perhaps we "know" that won't work, when in actuality the expert understands the topic so much more thoroughly that he can make it work, and work well.
Still...if the fish are kept in a large aquarium, carefully pre-conditioned and provided with all the cues that will trigger breeding behaviour...and then plopped into a tiny tank just before laying, and likely removed right afterwards...well, I guess that they did actually eject spawn in the small tank, but it is a bit disingenuous to just state that they were bred in that little fishbowl, without further explanation.
Not saying that's what was done here; I'd love to hear more. Sadly, the book seems not to be in English, so I am at a slight disadvantage...
I can't sure they had bigger tank but they seems to had some more tanks to raise parents fish because their report say about agression and some casualties while pairing so they needed some more parents fish.So does this mean that the fish are maintained in larger accommodations, and when they are properly conditioned and "triggered" they are moved to the small tank for the actual spawning? Much like we do for many smaller species, in an effort to control where they eggs are laid and then remove the adults immediately after spawning?
It's easy to forget that true experts, in any field, can "get away" with things that more casual hobbyists like most of us either would not be successful attempting...or perhaps we "know" that won't work, when in actuality the expert understands the topic so much more thoroughly that he can make it work, and work well.
Still...if the fish are kept in a large aquarium, carefully pre-conditioned and provided with all the cues that will trigger breeding behaviour...and then plopped into a tiny tank just before laying, and likely removed right afterwards...well, I guess that they did actually eject spawn in the small tank, but it is a bit disingenuous to just state that they were bred in that little fishbowl, without further explanation.
Not saying that's what was done here; I'd love to hear more. Sadly, the book seems not to be in English, so I am at a slight disadvantage...
But i can't sure about tank size because they breed almost all fish require bigger tank in 1800.600.600mm tank (include Asian arowana, Silver arowana, Brycinus sp. and Florida gars)
And if they had bigger tank, i think they use it for breeding.
