Fish March 2000

Tim Addis


This is the first Fish column to appear solely on the BKA website. A seperate column appears in the Newsletter which does not contain any Internet talk or links. The basic information contained in the Newsletter issue will still be put into this version along with webbie talk & links.

Re-vamp is the new thing as far as I'm concerned. Not only for the column but also for the Internet site too. The column has now been split into 2 separate issues. One for the Newsletter containing what it was originally designed for - i.e. information on breeding fish or tips & ideas & the other containing an additional input of hyperlinks to interesting websites.

Tony Pinto (an old name in the BKA & nice to hear from him) sent me one of those e-mail thingies in response to my plea for information on Aphyosemion. sp. OYO. Tony had a problem on sex balance with offspring as males were 10 times more frequent than females (I know a few towns like this & boy are those girls happy). Joking aside, what is the problem? Is it pH (most likely), temperature or what? Tony found fry in well planted tanks with the adults. Eggs were found to hatch in 2-3 weeks and fry sexed out in 3-4 months. Now, if it's relevant, I found that covering the egg container with a cloth helped prevent eggs going fungussed. Also, after doing this I found that as the back of the tank was now in darkness (due to the egg container being kept at the back of the tank) the egg production suddenly rose to 70+ a week with about 90% eggs remaining viable. OYO is located to the north of Gamboma, which is in turn north of Brazzaville. To me it looks a bit remote and is probably in a jungle biotope protected by shade.

On the AKA group site Andre Carletto replied to a question on Cynolebias and certain sp. survival in encroaching urban areas. Andre replied - 'Certainly the most endangered fishes are the ones whose habitats are close to big cities and/or development areas.' Andre also put in the fact that no Cynolebias sp. are currently on the CITES list of endangered sp. but Leptolebias marmoratus has not been found in the wild since 1947. L.sandrii being rediscovered in 1989 has not been found since 1993. C. whitei & C. constanciae were being systematically destroyed by the real estate industry but recent expeditions have found them still in the wild. 'Rio's Federal University lists all Cynolebias and Leptolebias from Rio as endangered or possibly extinct'. Other sp such as L.leitaoi, S.marginatus and S.auratus are in danger through road building projects. C. carvalhoi reportedly not found since 1937 was found in a well-populated area close to a clay extraction site.

Cynolebias carvalhoi

Cynolebias carvalhoi Black & White from Eduardo

Cynolebias carvalhoi

C.carvalhoi.One of the young raised from eggs sent by Eduardo in the '80's.

This photo was sent to me nearly 20 years ago by Eduardo Susena of Uruguay (now moved on). I had eggs of this sp. in 1984 and hatched 6 fry out. Myers' type locality is 1100 kms from the Uruguayan population between Carmelo and Nuevo Palmira. Whether it's the right sp I don't know. The CITES list basically is a joke. It was put together in the best possible way to preserve sp from illegal importation but really guys as far as killifish go you don't know what you're doing. How many killie sp can you think of that are either extinct or close to it yet as far as we can believe no killifish sp are on the list !!!

On reading Wolfgang's book on A. cameronense he mentioned using pumice stone as a medium in filters to establish colonies of nitrifying bacteria. I never heard of this before and I am thinking about thermalite blocks, which is of a similar construct i.e. very porous. These blocks can be cut to any shape with an old wood saw. I understand they are constructed from ash products but would like to know more from anyone more into it than I.

Here's a tip not found in the books - How can you tell if your water is just right for killies? Buy loads of test kits? I certainly don't. I don't even buy pH kits these days (BDH Indicator solution is good enough for any problems). How is it done? Ceratopteris or floating Indian Fern that's how. It only flourishes in slightly acid water, which by coincidence is what killies like. If the water starts to turn too acid or alkaline it stops growing. This plant grows extremely fast and any retardation of growth would be noticed. It's an early warning plant, which actually works. There you go another killie secret broadcast to the nation. Have you got any tips, which work for you? This column was set up for this stuff.

Cyclop-eeze is a relatively new product from the USA that is a powdered alternative to newly hatched brine shrimp. It's a red/orange colour and fry go mad for it or so we are led to believe. Basically it's cyclops freeze dried with colour enhancers (probably more to it than that). Brine shrimp prices at the moment are scandalous but these high prices come from the source so like the fluctuating mortgage rate we just have to grin and bear it.

Regional groups seem to me to be very close knit things. Group meetings throw up all sorts of ideas and tips but that's as far as it goes. What's the chances of taking along pen and paper to the next meeting and sending in some of these gems?

At a recent AKA show Jaap Vlaming did a talk on the effects of air pressure on egg production. This is something I have been convinced about since the '80's where I was trying to find an answer to why a lot of my tanks suddenly either started or stopped producing eggs. Air pressure seemed to be the obvious reason, as temperature remained constant. Jaap observed that savannah Aphyosemion were more or less annual in nature (regarding egg production) and that large numbers of adults could not be found following the rainy season. It would seem from this that the eggs would need to be layed in abundance 2-3 weeks before the rainy season. Jaap observed that the trigger for this upsurge in egg production could be a change to low air pressure prior to the rainy season starting. How can the fish predict when the rains will start? A question I have tried to find an answer to is - how long does it take for a female to convert food to eggs? They need to store up eggs to lay in this pre-rainy season period. Jaap put forward the theory that a lack of food in the dry season coupled with cooler temperatures acted as a trigger for the females to convert fat to eggs. I would love to experiment with this but with my job couldn't take eggs off and note air pressure on a daily basis. Perhaps someone with a barometer could do a daily log recording temperature, water changes, food given, barometric readings etc. The results could be most enlightening (or not).

Now then, on to webbie talk and the bits not seen in the Newsletter -

As my fish house has been more or less closed down for a couple of years I have never really used the net to find fish/eggs. As I have made some time now I can keep a few sp. going. I was encouraged by a contact I made from the DKG. The thread was 2 years cold but I decided to give it a go. Next evening an e-mail was received with an offer of exchange eggs. The sp. population I think has not been in the country before.

Brazilian hydrographics can be seen here : This site shows a map of Brazil with all the drainage systems for the country. About 5 pages of information here.

Weybridge - well what can I say. A record attendance of 80+ and only a couple of fish going for less than £2. In fact many fish were sold in the £5-7 bracket including fish unable to sell for a quid up north. Rod Roberts made a guest appearance as auctioneer and soon whipped up the prices (get that fish house going again Rod!).

Alan found two bedraggled Epiplatys a couple of months ago in a shipment. He had his suspicions as to what they were but kept me in the dark. Now he comes clean and tells me they are E. barmoiensis, which are very rare as I understand. What was even better news is they have started laying eggs.

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