Spencer Jack Biography

Spencer has been active within the aquaria hobby since the age of five. A true: cichlidiot”, he has worked exclusively with cichlids for over thirty years. He has since expanded his horizons to include all types of tropical fish.

Spencer has been an active hobbyist within Winnipeg for a number of years. Some of his roles within the fish hobbyist community include:

  • Co-founder of the Aquarium Society of Winnipeg (1989)
  • Founder and President of the Canadian Cichlid Association (2000)
  • Co-founder of the Dead Fish Order (2012)
  • Spencer now owns and operates a tropical fish business. The aFISHionados, and is still an avid fishkeeper and breeder.
  • Spencer’s enthusiasm, humour and dedication towards the aquarium hobby is easily witnessed through his lectures. All of Spencer’s lectures are full multimedia presentations using powerpoint, and almost all the pictures in use are original pictures taken by Spencer during his years in the hobby and travels across North America, South, Central America, and beyond.
  • Spencer is a part of the American Cichlid Association speakers program.

What’s New In Cichlid Studies: Part 2

BREEDING BEHAVIOUR: GETTING A PAIR

The greatest challenge in spawning cichlids in the home aquarium seems to be getting the pair to do their business and churn out the fry. Assuming one has a male and a female, which is not always easy to select in some species, the problem is to ensure that they mate and produce fry without killing each other. Aquarists often try to breed a pair of cichlids in an isolated tank. This may be necessary if the only available tanks are too small to sustain a community of fish. Given a large enough tank, however, it is known that it is often easier to breed cichlids if there are some dither fish with them.

Dither fish may be other cichlids of the same or different species, but need not be. They can be cyprinids or other speedy fish that distract the breeding pair’s aggression from each other and focus it outward against the dither fish. It was recently demonstrated with experiments on angelfish that pair bonding is maintained when there are intruders to defend the nest against [1]. Monogamous marriages among angelfish are the result of a mutually defended territory, not an altruistic feeling.

Aquarists often have trouble selecting a male and a female of a cichlid species. The best method is to raise up six fry and let them do the selecting, but that is not always possible. Even for the fish themselves, they sometimes have trouble. This was shown with a study on three closely related Lake Malawi cichlids where males were isolated from various females by glass so they only had visual cues to go by. Pseudotropheus males in the study could identify females solely by sight in some species, but in other species the males were unable to correctly select females by sight alone [2]. This suggests that olfactory cues, that is, the scent of the females in the water, may play a part in pair formation. Sound production was ruled out in this experiment, but it is known to be used by other cichlids. Given that even the males (who should know) have trouble identifying their own female conspecifics, it is not surprising that aquarists trying to do their own matchmaking have hybridized Pseudotropheus species unwittingly. All those bland females look alike but are not alike in the gene pool.

Courtship may involve sounds, although aquarists may not be able to hear the serenades. The males of two Malawi cichlids are known to produce pulsed sounds while courting females, those being Tramitichromis cf. intermedius and Copadichromis conophorus [3].

RAISING THE FRY

One peculiarity of some Tanganyikan cichlids is that juveniles will help older fish raise fry, such as assisting in mutual defence of territory. Neolamprologus brichardi is well known for this behaviour. A swarm of such fishes on a rock pile consist of parents, their young fry, older juveniles, and unrelated juveniles from elsewhere. Such altruism gives the brood care helpers experience in learning to raise children for when their own time comes. Aquarists should not be too hasty in breaking up hatches of such fish if all else is well. Indeed, what may contribute to cichlid mayhem and murder in aquaria, besides too-small tanks, is that many fry are siphoned out and raised separately. They never learn the social cues that enable fish to get along, much as the problem with most human juvenile delinquents is that they are from broken homes where they never learned proper behaviour. When they are sold off and placed in new homes, the isolated fry cause difficulties in breeding.

Sometimes altruism in habitat loses precedence to selfish DNA. Neolamprologus brichardi juveniles greater than 4.5 cm standard length are mature. Mature enough, in fact, to take an interest in the lady of the house, just as a human boarder may cuckold the landlord with his wife. Such fish will try to parasitize the spawning of the parents. Even if they only succeed in fertilizing a few eggs, that is better than nothing. The male of the pair does not take this lightly, anymore than a landlord would when he finds his wife in bed with the boarder, and the parasitic breeder will be driven out of the rock pile. The study that uncovered this determined that 4.5 cm is the boundary line before such a thing happens [4]. From a practical point of view for the aquarist, it would therefore seem logical to start taking out juveniles at that length or perhaps even 3.5 cm, which is the length at which Neolamprologus brichardi is sexually mature.

Mixed schools of fry may not only contain fry from different parents but also different species. The Tanganyikan cichlids Lepidiolamprologus elongatus and Perissodus microlepis often have 20% to 40% foreign fry of other species in their schools [5]. The parents are well aware of them but seem to tolerate them because the hassle of trying to evict foreign fry would attract the attention of predators. It would not be easy tracking and chasing one certain fry in a cloud of them and killing or evicting them.

WHY CAN’T WE ALL JUST GET ALONG?

A basic principle of ecology is that the more closely two species live in similar habitats, the more antagonistic they are to each other. An algae scraping cichlid does not worry about a mid-water feeder, and a cichlid that munches on snails is not upset to see an algae feeder nearby. (This assumes no breeding territorial functions are involved; if fry are being protected, then parental instincts override feeding behaviour.) For very dissimilar species, scientists have no trouble establishing this principle. Things get complicated when apparently similar species tolerate each other in the same territory. Is this because scientists haven’t identified the different behaviours (which have only micro-differences)? Or is it because the fish really use the same behaviour and the theory is wrong?

The Rift Lake cichlids have attracted scientific attention on this point because of similar species co-existing. One case study involved Lobochilotes labiatus, a Tanganyikan crevice feeder [7]. These fish have large fleshy lips; they suck shrimp, mayfly, caddis fly, and midge larvae out of crevices. Feeding territories of similar-sized fish do not overlap, which is expected, since they would be competing for food. However, there was little aggression between large and small individuals. Analysis showed that the large fish worked large crevices and the small ones worked small crevices, thus separating their feeding microhabitats even though they overlapped on a larger scale. The difficulty in determining overlaps or not was seen in another study on a number of Lake Malawi cichlids [6]. Many species apparently co-exist despite using the same feeding niches, although most differentiate their food sources. Further study will be required in habitat.

But further study can also be done by aquarists. Granted that a home aquarium is not a true representation of a Rift Lake; the biggest, most sophisticated aquarium can never fully duplicate wild conditions. But that is no reason not to study your fish and observe what they are doing. Professional ichthyologists will never be able to examine the behaviour of all the cichlids. Aquarists can fill in the gaps. Home research may not be as rigorous as professional research, but it can often suggest leads for others to follow. This does require communicating what you have learned in watching fish, the easiest way of which is to write up your observations for your club bulletin. Since most clubs exchange with others, your article will be read by more people than you imagine, and some of them are ichthyologists.

REFERENCES.

1] Yamamoto, M.E., S. Chellappa, M.S.R.F. Cacho, and F.A. Huntingford (1999) Mate guarding in an Amazonian cichlid, Pterophyllum scalare. JOURNAL OF FISH BIOLOGY 55:888-891

2] Knight, M.E., and G.F. Turner (1999) Reproductive isolation among closely related Lake Malawi cichlids: can males recognize conspecific females by visual cues? ANIMAL BEHAVIOUR 58:761-768

3] Lobel, P.S. (1998) Possible species specific courtship sounds by two sympatric cichlid fishes in Lake Malawi, Africa. ENVIRONMENTAL BIOLOGY OF FISHES 52:443-452

4] Dierkes, P., M. Taborsky, and U. Kohler (1999) Reproductive parasitism of broodcare helpers in a co-operatively breeding fish. BEHAVIORAL ECOLOGY 10:510-515

5] Ochi, H. and Y. Yanagisawa (1996) Interspecific brood-mixing in Tanganyikan cichlids. ENVIRONMENTAL BIOLOGY OF FISHES 45:141-149

6] Genner, M.J., G.F. Turner, and S.J. Hawkins (1999) Foraging of rocky habitat cichlid fishes in Lake Malawi: coexistence through niche partioning? OECOLOGIA 121:283-292

7] Kohda, M. and K. Tanida (1996) Ovelapping territory of the benthophagous cichlid fish, Lobochilotes labiatus, in Lake Tanganyika. ENVIRONMENTAL BIOLOGY OF FISHES 45:13-20 ?

Bagging Your Fish for the Auction

Please take the time to bag and label your fish properly to ensure their health / safety enroute to their new homes. Here are a few simple guidelines:

  • Avoid feeding your fish for 36-48 hours prior to bagging. This greatly reduces the amount of waste that will accumulate in the bag while also keeping harmful ammonia levels to a minimum.
  • Use proper fish bags and elastics when bagging your fish (ask for these items at your local aquarium supply shop). Ziplocks are not reliable for holding water and air under pressure so should be avoided. Use ziplock bags only for dry goods… they’re also good for a ham sandwich! ;)
  • Allow for a ratio of approximately 75% air / 25% clean tank water in each bag for maximum oxygen levels and to keep your fish comfortable. The water should cover your fish while the bag is on its side… keep in mind oxygen is more important than water. At this point you could optionally add a small amount of conditioner (or de-stressor) to the water.
  • Use fresh air in your bag – avoid ‘blowing’ air directly into it. Simply open the bag as wide as possible and then quickly snap your hand around the top to seal in a good supply of fresh air. (An air pump could assist.) Use elastics to close the bag, and secure well. The bag should be taut like a balloon.
  • Double-bag your fish if they have sharp fins, teeth or bristles (i.e. anything ‘pokey’). Hint: medium-to-larger-sized cichlids, catfish, sucker fishes / plecos are all common suspects!
  • Always bag medium-to-large fish in separate bags. When deciding how many fish to put together in one bag, consider whether or not they all appear to have enough room (i.e. if the bag were accidentally bumped, would any fish collide with each other?) Fish that are naturally aggressive by nature should be bagged separately (i.e. each aggressive fish gets its own bag!)
  • For any unusually large fish, avoid using fish bags and instead choose a suitably-sized plastic container (pail or bin) with lid to be sold along with the fish. The lid should seal properly but be easily removable in order to properly show the fish.
  • Do your fish take great pleasure in jamming themselves into the corners of the bag? While stuck in a corner of the bag, they may not be able to breathe properly and could injure themselves. A quick-fix to this problem: turn the bag upside-down, and then double-bag for safety. Voila — no more corners!
  • Are your fish accustomed to living in a tank with aquatic plants? If so, adding a small plant, stem or a few leaves in your fish bag will provide added comfort and shelter for your fish while they wait.
  • Please label each bag clearly with the following details: vendor-lot number, species name, number of fish in the bag (unless it’s just one), and whether the fish are male / female (if known). If you wish, you can also include additional information such as: species origin, an adult photo of the species if your fish is a juvenile (or use a photo of the juvenile’s parents), the generation if known, etc… Be sure your bag labels are clearly visible and easy-to-read. Hint: the more information you can provide to the auctioneers, the more easily they can sell your fish to a suitable home, and for the best possible price.
  • If more than one fish bag is to be sold as a single lot, mark each bag with the vendor-lot number and also mark each bag as being, e.g. “1 of 3″, “2 of 3″, “3 of 3.” Be sure to use tape, a larger bag, etc. to keep all bags within each lot together as one unit so that the individual bags don’t become separated, or get confused with other lots nearby.
  • When transporting your fish to or from the auction, use a foam container or cooler box (e.g. a camping cooler) to keep the air around the bags steady at room temperature. As an inexpensive alternative (though don’t use this method for extended periods of time as it’s a bit less effective), you can also use triple-bagged paper shopping bags (e.g. paper Co-op or Safeway bags) with extra newspaper inside, then and roll up the top to keep any outside cold air out. Whichever method you choose, it is especially important for your fish to be insulated when traveling on winter days.