Kelly

Photo by Phoenix44
Author: Bryan Jones, Auckland Fishkeepers Association
First published in Aquarium World Magazine November 1988
With this article I hope to encourage FNZAS members to have a try at breeding one of the most popular tropical fishes worldwide – the cardinal tetra, Paracheirodon axelrodi. Cardinals have been spawned in NZ but, to my knowledge, this has not been maintained on a regular basis. From time to time since obtaining my first cardinals about 1960, successes have been obtained in my fish room but not continually such as with other tetras including neons, rummy-noses etc.
The cardinal tetra was introduced to aquarists in the late 1950’s and was considered to be the most strikingly coloured freshwater fish since the arrival of the neon tetra in the 1930’s. A large school of cardinals in a suitably aquascaped aquarium is a stunning sight, particularly if attention is given to subdued lighting, dark substrate and quality water.
Cardinals are frequently available in many NZ retail petshops, usually priced from $5 – $10, and are virtually all from wild caught stock. They are not a cheap fish compared to, say, the neon tetra at $1.50 – $2.50 each. This is probably why many NZ aquariums, although displaying a few cardinals, seldom house a large school of 50 – 100 which would give a much more visual impact. The main reason for this is cost, as the hopes of commercial aquaculture breeders overseas to mass produce cardinals following their introduction has not, to date, been achieved – unlike what has been done by the Chinese in rural Hong Kong with the many millions, per annum, of neon tetras bred for the world markets.
Following the discovery of cardinals by Dr Harold Sioli in Sept. 1952, near Sao Filippe in the Rio Negro region, wild caught cardinals supply the world markets. Many millions are exported from Brazil, and to a lesser degree Colombia, each year (40,000,000 in 1996). This is an important income earner for the local populace centred around Barcellos on the Rio Negro, 386kms upstream from Manaus, where most are flown overseas to world markets.
There is concern that a large number of cardinals captured do not survive the first stages of export (up to 50 million PA) and efforts are now being made to reduce such losses. Further more, due to the large demand for this species (which is the highest exported ornamental fish by far from Brazil) they are getting harder to catch. What took one day some years ago, now takes one week for the same number, and the fishermen must travel further afield. There are concerns that more attention must be made to control the fishery, which could mean a limit on volumes taken and closed collection periods, to protect cardinal exports in the future.
For the intending breeder of this fish, a study of the bio type is of interest. Cardinals do not habit the main Rio Negro river or its tributaries but rather their source in dense forests and swamplands. In the rainy season, December to March, when many waterways and lowlands become flooded, cardinals move further upstream over areas that were dry, or at best only swampland, in the drier months. This is the time when cardinals breed, stimulated by fresher water, extra food availability, and temperature changes.
A common myth is that cardinals breed in water that is dark brown and very peaty with low acid readings more relevant to the water found in main rivers in the dry season. The water, however, at all times in this area is very soft due to soils having the lowest mineral content in the world. The water during the heavy rainy season, when the cardinals breed, is therefore further softened and acidity diluted as shown in low hardness and conductivity readings. Another factor to be noted in this bio type is that cardinals are found only in dark and shaded waters away from sunlight and they have a distinct dislike of strong light.
If you are interested in producing, say, 500 cardinals, now is the time to purchase some breeding stock. About 20 will be needed and should be young imported fish, not old fish from established aquariums. Set up a 60 x 30 x 30cm aquarium with a black painted bottom, back and sides, subdued lighting, and soft water. Use no substrate which could harden the water. Plants can be kept held down with waterlogged driftwood. A plastic box type filter is appropriate using glass wool and a little peat to slightly acidify the water but provide water changes as needed to keep the conductivity low ie Below 200 micro-siemens.
A varied diet is needed including daphnia, white and blood worms, and particularly brine shrimps, to bring our growing cardinals into breeding condition. Consider setting up a sea monkey tank to provide larger brine shrimp adults for your breeding stock. I have a 45 x 23 x 23cm tank sitting on a window sill in the fish room containing salt water of .130 specific gravity and provided with strong aeration. The shrimps grow to about 1cm in a month if fed on a yeast and water solution which I keep in a plastic 1litre lemonade bottle. Feed a little regularly only when the salt water tank clears by the shrimp eating the food.
As we will be testing the hardness and pH values of our water conditions, I would suggest the purchase, or acquisition, of a conductivity and pH meter. I have one of each which I use for quick and accurate tests when required.
Raising the Fry
With a lot of tetras, obtaining the eggs is the easiest part. Raising large numbers of fry is the real challenge!
After 5 days, and not before, remove the covers and check for results; either with a torch, or place the tank on a shelf with light from behind. If all has gone well, we can see small fry shooting around the bottom edges of the tank and through the peat fibre. There will be many more hiding in the peat so don’t think that sighting only a small number is necessarily a poor result.
At day 6, when their yolk sacs are used up, they should be free swimming and must be fed. Use a magnifying glass to check if the fry are actually swimming, rather than just hopping about while still having some yolk sac left. Water temperature will have an effect on this time as a higher temperature will shorten the hatching process.
This is a critical stage when many, or all, of the fry can be lost due to starvation, feeding too late, too soon, or too much resulting in sudden water pollution.
Cardinal tetra fry can take brine shrimp from day 1 as long as it is the right sort. San Francisco Bay brine shrimp eggs are the ones to use as these are significantly smaller than the Great Salt Lake, Utah, eggs. SF Bay eggs are in demand by the aquaculture industry world wide, mainly for marine and shrimp aquaculture, ahead of the freshwater hobbyist. Don’t be fooled by packets sold as San Fransisco Bay BRAND and other labels without checking the source of supply. You will find that they ‘originate’ in Utah ie. The larger eggs. The shrimp to feed our cardinal fry on days 1 – 4 must be ‘just hatched’ not 12 hours or more after hatching as they will have grown to a large size and are too big for the little mouths to take. Use clean sea salt water and position jars in a sunny and warm place, providing strong aeration, to get a good brine shrimp hatch.
Feed fry morning and late afternoon, but only small amounts. Use an eyedropper measuring a drop or two into a glass of water to inspect the volume of shrimp before carefully adding to our fry tank. After half an hour, check that the fry have orange bellies; If so, we are over the hard bit unless we get slack and overfeed with brine shrimp which will pollute the water. If there are signs of orange shrimp on the peat, you are overfeeding. After 4 days use any brine shrimp, and microworms, if available.
After 4 or 5 days commence removing, and adding, small amounts of matured water at the same temperature and conductivity each few days to raise the tank level up to 20cm. I have a 15mm diameter plastic tube siphon which has a bulb shaped gauze end wrapped with a piece of nylon stocking for these jobs. The nylon is too fine for fry to be sucked up but inspect it for holes regularly.
After 2 weeks, and when there is sufficient water height, add a small sponge type filter which will help keep the water in top condition. From the 3rd or 4th week the fry should be swimming clear of the peat and start to show some colour and hopefully we have produced +100 young cardinals.
Subsequent spawning from our breeding stock should produce higher numbers. Don’t try to separate fry from the peat until they are over 10mm. Careful use of a larger plastic siphon, to remove peat and water from one end of the tank, is probably the best method. Check the contents after it has settled for any fry inadvertently picked up, and catch these with a small net.
When moving fry around to larger growing tanks, ensure the water quality and values are similar using your conductivity meter. Young fish do not take kindly to sudden changes and our hard earned labours can result in heavy losses. Always balance the water when moving from one tank to another.
Keep a record of details of your fish breeding attempts as they can be useful in the future. At the end of this article is a copy of the form I have used on occasion and may be of assistance. I wish every success to those of you who are going to give breeding cardinal tetras a go. I look forward to reading in the Aquarium World listings from the breeding co-ordinator of the beautiful cardinal tetras being recorded on many occasions. Who knows when the wild supply will be fished out or restricted by price (or whatever other reasons) to the NZ hobbyist.
Breeding Methods
When your cardinals have grown to adult size, 30 – 35mm, and about a year old, the fish will need to be sexed and placed in separate aquariums, or separate your growing aquarium with a glass partition. The females must be heavy with roe; hold them in a net up to the light and you will see eggs in the body cavity. Males have a thin, pointed cavity and a slimmer profile.
In the meantime, whilst you are feeding your split breeders, set up the breeding tanks. I use 45 x 23 x 23cm glass tanks which are sterilised with potassium permanganate (KMnO4) – including airstones, tubes, cover glass etc. I would suggest setting up three tanks, so that we can increase our chances of a hit, or maybe to six tanks if you are the determined type like me and want results.
For the substrate and egg catchment, I use peat moss that has been water logged for some months and then boiled up to achieve sterilisation. The cooled peat can then be spread into the breeding tanks to a depth of 2cm.
Previously collected and matured rain water, with a conductivity of 20–60 micro-siemens, is then added slowly through a small plastic tube, to avoid stirring up the peat, to give a depth of 12cm. Leave the tanks in a dark place with cover glass on, and very slight aeration, for 2 weeks. The water should now be clear with a slight brownish tinge but the conductivity should not have changed more than a degree or two. The peat will provide a natural substrate and hiding place for the eggs; act as a bacterial reducing agent, and will slightly lower the pH value of our rain water. A pH value of 6.5 – 6.6 is about right. I do not use nylon mops or plant.
Concerning temperature, for those of you who do not have a heated fishroom, we need to aim for a water temperature in the high 70’sF (26º – 27ºC). The problem with having a glass heating element in the spawning tanks is that they will burn small hatched fry if they hide and settle on the heater. Better to use heating pads, as discussed in a recent Aquarium World article.
To keep tanks in subdued light, I wrap them in black polythene with a window strip cut out in the front to about halfway down to observe for any eggs.
I introduce two females and two males to each tank hoping that at least one will drop her eggs, which is usually after the third day. Cardinals take some time to settle down to new surroundings and the peat substrate and masked sides of the tanks will help with this objective. Community spawns have been achieved but this can result in smaller numbers due to other fish using the occasion for an egg feast. Fertile eggs are clear and non-adhesive.
Cardinals spawn at night, so look for the odd white unfertilised egg or two on the peat each morning with the quick use of a torch and eye glass. Do not feed the fish in the spawning tank. If you see the odd white egg, your cardinals have spawned and many eggs will be hidden in the peat, especially round the edges of the tank. Carefully remove the adults and cover the tank completely to block out all light. After the spawning, I add 5 drops of 5% Methylene Blue to help sterilise the water from bacterial growth.
The female fishes which spawned should be a bit slimmer and are the ones to keep identified in a separate holding area. These fish, if well fed, will breed again in about 14 days. As with other tetras, it is essential to regularly spawn these young, breeding females to allow for continuing egg production and not to stagnate and harden the eggs in the ovaries of unmated females. Better numerical results of fry are achieved after one or two spawnings. I have bred cardinals without peat substrate using 3mm stainless steel mesh grills to protect falling eggs from hungry parents. You will need to hold rain water in a large plastic container with the peat bagged in a nylon stocking which is hung in the water for a month or two. When the water is clear, with a brownish tinge, the pH about 6.5 and conductivity 20–60 micro-siemens, set up your breeding tanks as before. I, however, prefer to use the peat method, despite separation problems with the young fry later, as the peat is a more natural substrate and tends to relax breeders more than in a bare tank.
Some points which I consider facilitate success; My best results have been during hot summer months when day temperatures in the fish room were over 26ºC. Full moon periods when spawnings resulted have been noted. Consider the use of a very low wattage light overnight, some distance away from your breeding tanks, to simulate moonlight. The use of slightly older male fish that may have bred before seem to be better drivers of younger, virgin females.
If no eggs are seen after 7 days, remove the adults and return them to the holding tanks for further conditioning. Try again after a few weeks. Try replacing most of the water with matured rain water and next time use different fish, ensuring the females are full of roe.
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Bullies
Author: James Cooper
First published in Aquarium World August 2013
 
Introduction
Attractive, tough and full of character, Bullies are a hardy and easy to obtain New Zealand native fish. The name bully is short for Cock-a-bully, a name given to these fish by the early European settlers; it is thought the name is a mispronunciation of ‘Kokapuru’ the Maori word for small fish.
Cran's bully male (Photo credit Charles Fryett) 
Bullies live in a wide range of habitats throughout New Zealand and most varieties are common, although this status is being threatened by the spread of predatory Brown Trout and invasive pest species such as Gambusia as well as the reduction of habitats.  Most species are endemic to their specific habitat but occasionally species can be found co-habitating in prime areas. Bullies can change colour depending on season, mood, and breeding behaviour. Colouration can even vary within the same species for specimens found in different environments around the country so it can be a real challenge to definitively identify them.  Bullies are generally hardy and easy to obtain, living for around 3- 5 years, and they have an inquisitive personality so are the perfect candidate for someone interested in having a go at keeping New Zealand natives.
Setting up an Aquarium for Bullies
Bullies are cold water fish and need to be kept below 20°C to be comfortable.  The best way to achieve this is to keep an eye on the room temperature and if it is nearing 25°C, a few ice cubes, floating a frozen bottle of water, or a fan directed at the water’s surface can bring the temperature down.  If you are serious about keeping New Zealand natives it is wise to consider a chiller unit and although rather expensive, they allow you to keep the tank consistently cooler which will ensure you have happy, healthy and therefore beautiful fish.
Most bullies are medium sized fish (10-25 cm) so they are one of the best native species for smaller tanks.  A good minimum size tank for 3-4 adult 10 cm bullies is a standard 2ft tank (600mm x 300mm x 300mm) however they are bottom dwellers so it is more important to have a large footprint rather than a lot of height in the water column. As is standard for all fishkeeping, the bigger the better and a larger tank will allow you to keep water parameters more stable as well as allowing the introduction of other New Zealand native mid-water fish such as Inanga (Galaxias Maculate) or Smelt (Retropinna retropinna or Stokellia anisodon).
The tank substrate should be fine sand or gravel substrate and include lots of rocks, driftwood and other areas of cover for the fish to reduce stress.  Tank lighting is not essential for Bullies as they are normally nocturnal in the wild and bright lighting will usually make them run for cover. To allow for good viewing of the aquarium, dim lighting can be used and as they get used to this, they will come out more often.
Collecting Bullies in the Wild
Taking fish from the wild is a big responsibility. Once a fish is removed from a native habitat, it is illegal to release it back into the waterway (this also includes plants and invertebrates) so you must be prepared to care for it before you go out collecting.  Most native fishes are nocturnal so catching them involves venturing out in the evening for spotlighting in waterways. To capture Bullies, it is best to use a two-net approach, with one large net slowly drawn up behind the fish and another used to scare the fish downstream into the waiting net.  A good quality headlamp is a must in this situation. Another approach is to set bait traps with a bit of bread into a quiet pool or along the river bank or lake; these traps can be purchased at most fishing tackle stores. 
Night time spotlighting (Photo credit Charles Fryett)
Once captured, it is important to identify the species.  Juveniles (around the 3-5cm mark) are the best as they will adjust to the home aquarium a lot better than an older specimen. 
Once you have your fish home it is important to acclimate the fish very slowly.  The easiest way to do this is to use the ‘drip’ method favoured by marine fish keepers.  This is accomplished by placing the fish in a bucket below the tank, and using a length of standard air-hose.  Start a siphon down to the bucket, clip or a loose knot in the hose will allow you to control the flow of water - the aim is for the water to flow at around one drip per second. Once the bucket is full you can net out the fish and add it to the tank.  It is best to avoid adding the water from the bucket as it may contain high levels of fish waste.
Behaviour
Most bullies are rather peaceful and tend to be friendly to other tank mates except around breeding time, even then most squabbles are harmless.  They will however eat anything that they can swallow whole so this must be taken into account when choosing tank mates.  Apart from this, they are very well behaved and inquisitive, known for spending a lot of their time watching the outside world and enjoying vantage points on which to perch for a better view, often pushing each other out of the way to get the best spots.
Feeding
Most bullies will transfer onto a diet of standard dry food quickly, however it is best to use a sinking pellet type rather than a flake as it holds together better and causes less pollution in the tank.  Frozen bloodworms are useful as a treat but should not be used as a staple diet as they are nutritionally lacking.  Another good alternative is a prepared food with ox heart and a variety of vegetables, there are a range of recipes out there and a quick search will provide you with one you can use.  The benefit of this food is that you can control what goes in to it and ensure your fish get a balanced diet. If available, live food is a great option, there is a variety of easily cultured foods available such as daphnia, whiteworms, blackworms, maggots or earthworms which provide a lot of nutritional value as well as promoting the fish’s natural hunting behaviour.

Cran's bully eggs 20+ days (Photo credit Charles Fryett)
Breeding
All bullies are cave spawners.  Normally during spring or summer the male will set up a territory within a cave-like structure, normally the side under a rock or log. The male adopts a dark colouration, almost black in some species.  The female will deposit a number of eggs inside the cave and then leaves so the male can guard the nest until the larvae hatch.  This takes up to several weeks, the time is temperature dependant.  Some species spend their larval stage around the place they were born; some migrate down to sea and return once they have reached a certain size.  One (the Tarndale Bully) even has free swimming pelagic larvae.  The only types that can be successfully bred in the home aquarium are the Upland bully and the Crans bully.
Common Bully - possibly male (Photo credit Charles Fryett)
Common Bully
Gobiomorphus cotidianus
Found throughout NZ and the most common bully as its name suggests, it is found in lowland areas around coastal rivers and lakes.  It is normally not found far inland as it is not known to be a great climber like some of its couterparts.  This bully is one of the best for beginners due to its amazing hardiness - this is not to say it should be mistreated as a well kept specimen is a sight to behold.  Grows up to 15cm, matures at around one year old and lives for 4-5 years.  It is a sea run spawner but there are landlocked populations that complete their entire lifecycle in fresh water.
 

Giant Bully (Photo credit Charles Fryett)
Giant Bully
Gobiomorphus gobioides
The largest of the native Bullies gets to a length of 24 cm and is commonly found in the lower reaches of rivers and even into brackish water of estuaries. They rarely travel far upstream from their home habitat.  Juvenile Giant Bullies and Common Bullies are hard to distinguish from each other; the rule of thumb is that Common Bullies have seven spines in their first dorsal fins and Giants have only six.  Another clue is that the lower jaw of Giant Bullies extends past the top lip where as in Commons the jaws tend to be more equal.
Giant Bullies can be a bit aggressive to other smaller tank-mates and they also like to hide under overhanging banks and in heavy cover so they not only require a larger aquarium than other bullies, but they also appreciate adequate cover and hiding places.
 

Red fin bully (Photo credit Liam Winterton)
Redfin Bully
Gobiomorphus huttoni
The jewel of New Zealand native fish is the spectacularly coloured Redfin Bully where males of the species have brightly coloured finnage and variable body colouring with bright yellows, reds and iridescent greens. During breeding they will turn a solid black with a bright green edge to their first dorsal fin. Females have fewer colours but still have the diagonal facial stripes that are a tell-tale sign of this species. They are a smaller bully only reaching a maximum of 122mm (females are smaller growing) so are perfect for the smaller aquarium or species only tank. They are found NZ wide and are well accomplished climbers found well inland even past significant barriers such as waterfalls. Unfortunately, they are a sea-run2 fish so have not been successfully bred in the home aquarium.

Bluegill bully (Photo credit Stella McQueen)
Bluegill Bully
Gobiomorphus hubbsi
This little stunner is an inhabitant of faster flowing water and loves a strong current to play around in. Bluegill Bullies have a longer more streamlined body-shape that is perfectly adapted for living in fast flowing rapids of new Zealand rivers. The Bluegill Bully is also a smaller growing species, only reaching 93 mm. An aquarium for these beauties requires a strong water flow and a lot of surface movement to ensure high amounts of oxygen like those found in its natural habitat. With careful placement of stones you can create calmer areas for the fish to rest and feed right. Found New Zealand wide, the Bluegill has a sea-run larval stage and are very short lived, living only to around 2 or 3 years maximum.
 
Cran's Bully male in breeding colours (Photo credit Charles Fryett)

Cran's Bully male with large female (Photo credit Charles Fryett)
Cran's Bully
Gobiomorphus basalis
Short and squat, these fish can only be described as cute. Crans Bully bodies are mottled with sandy browns and olive greens, the males sport a bright pink/orange margin to their first dorsal fin. As the males age their heads become more blunt and bulbous. They are found mainly in inland rocky streams throughout the North Island except in the Bay of Plenty region from Waihi to East Cape. These Bullies are one of the landlocked bullies that can be successfully bred in the home aquarium. It is one of the most common species in the North Island and  grows to a maximum of 92 mm.

Upland Bully (Photo credit: Stella McQueen)
Upland Bully
Gobiomorphus breviceps.
A distinctive bully with a lighter grey/brown base colour than most of the more coastal bullies and irregular brown patches and orange/brown spots. Males are stouter and have a blunter head that gets more blunt with age and a orange fringe to the first dorsal fin and a light orange patch at the base of the pectoral fin. Females lack the orange. As its name suggests it is found in upland areas throughout the South Island and in a few rivers and streams of the southern North Island. It is a fully freshwater species and can be bred in the aquarium.  This is a slightly larger species growing to a maximum of 135 mm.
Tarndale Bully
Gobiomorphus alpinus
Here more out of interest than for actual keeping, the Tarndale Bully is NZ's smallest bully with a maximum recorded size of 75 mm.  It is also interesting in that its larval stage, although freshwater it is also pelagic1.  It is only found only in the Lakes of Tarndale Station in Molesworth, near Marlborough and in the upper Clarence river system and Wairau river. The Tarndale Bullis are slender and rather big-headed but otherwise hard to distinguish from the Common Bully. They are not technically protected, as are none of our living native freshwater species, but considering their rarity, it would be considered ethically wrong to attempt to collect it without proper consent and knowledge of the relevant authorities. Being only found on private property, trespassing laws would also apply.
1 Pelagic fish live near the surface or in the water column of coastal, ocean and lake waters, but not on the bottom of the sea or the lake. http://en.wikipedia.org/wiki/Pelagic_fish
2 Sea run – Spawning takes place in fresh water and after hatching the larvae are swept out to sea.  As juveniles they return to fresh water where they spend their adult lives.
Further reading on Bullies:
The Reed Field Guide to New Zealand Fishes; R. M. McDowall; 2000
Ikawai – Freshwater fishes in Maori culture and economy; R. M. McDowall; 2011
The New Zealand Native Freshwater Aquarium; S. McQueen; 2010
A Photographic Guide to Freshwater Fishes of New Zealand; S. McQueen; 2013 
FNZAS Native Freshwater Fishes; FNZAS/C. Fryett; To be published
 
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