Nov 082013
 
Finke Goby

Finke Goby

Photo – Gunther Schmida

Introduction –
A care sheet is to help you keep and breed your small gobies to be able to keep them going and have spares to give to your friends. The Finke Goby is on the Northern Territory threatened species list as vulnerable because of its restricted distribution. It is restricted to the Finke River near Alice Springs in the Northern Territory. The brood stock were collected under the provisions of a NT Fisheries License.

General Information about habitat and the goby.
The Finke River is usually a series of water holes and flows after periods of heavy rain. It has nine species of fish recorded from its waters. It flows through the Macdonald Ranges near Alice Springs then in a South Easterly direction where it eventually disappears into the desert. It is reported to be one of the oldest still running rivers on the planet.

The waters in the Finke River can be quite cool with temperatures between about 10 Deg C to over 30 Deg C depending on the seasons. The salinity ranges from pure fresh to saltier than the sea.
pH from 7.5 to 8.5
Carbonate hardness from 80 ppm to 240 ppm
Hardness from 40 ppm to 240 ppm

This makes the fish within this old desert river great survivors generally able to tolerate broad ranges in their water quality. The Fink Goby grows to approximately 5.5 cm, it is a bottom dwelling fish and after swimming it slowly sinks back to the bottom because it has no swim bladder. Their natural diet is reported to be aquatic insects, small crustaceans and algae.

When the fish are larger they are relatively easy to determine the sex differences. The males have larger heads and a slender body, their fins are bigger and more colourful than the females. The females also have more plump bodies.

Captive husbasndry techniques
I will suggest a small aquarium of approx 50 litres to 60 litres, about 60 cm X 30 cm X 30 cm is ideal. An aquarium this size will house six to 12 Finke Gobies comfortably. A simple effective filter would be an under gravel style of filter with approx 3 to 4 cm of fine shell grit as a substrate. The shell grit will help maintain a bit of water hardness. It is also adviseable to have some places for them to hide. Small logs, some rocks and large leaves arranged to create small caves and crevices.

Water quality management for most small aquariums is similar. Put a heater in the aquarium to keep the temperature about 20 to 25 Deg C, keep the hardness about 100 to 200 ppm, keep the carbonate hardness over 60ppm.

Foods to offer your gobies can be flake but not recommended as a staple diet. It is suggested to offer thawed frozen foods, blood worms, brine shrimp or prepare your own frozen foods with a home blender or mincer. All these foods should be offered sparingly to prevent fouling the water. A good frozen prepared food is equal portions of fish fillet, prawns and peas. All ingredients are frozen in small chunks then passed through a hand crank mincer with a 2 or 3 mm plate. The result can be mixed with about 100 grams of calcium ascorbate per one kg and frozen into thin one centimeter slabs. Pieces can be broken off and fed when required. This prepared food is good for many omnivorous forage fishes.

Breeding notes
This small forage fish breeds easily in the aquarium. Just put a few pair in a 60 cm aquarium, feed plenty of small live foods until the females are plump. Place some flat srones, small sticks, large dead leaves and a few pieces of PVC water pipe 15mm diameter cut to 15cm lengths. Put the openings in a place where you can observe the inside of the pipe. Males will get broad in the head and become more colourful eventually the female will go into the pipe with him and they weill lay eggs on the inside of the pipe. The eggs stick to the wall of the pipe and will be guarded and fanned by the male until they hatch. You can then move the adult fish to another aquarium and continue to feed the small ones finely minced recipe the same as the adults are fed.

They will grow quite quickly. Give them to your friends with their story. Do something to raise awareness of conservation issues. If you sell some of these think about sharing the cash with the Traditional Owner of the Finke River near Henbury. Peter Abbott of Wallace Rockhole via Alice Springs. He could use the cash for the landcare work in the area. The waterholes along the Finke River are degraded by feral donkeys and camels.

If you want to keep these little fishes long term you should breed them often, they only live for two years probably less.

References and further reading
Allen G.R., Midgley S.H. and Allen M. (2002) “Freshwater Fishes of Australia”. ANGFA database – http://db.angfa.org.au

Jun 292013
 

 

Reticulated Glassfish from Adelaide River NT

Reticulated Glassfish from Adelaide River NT

Common Name:                        Reticulated Glassfish

Genus species:                        Ambassis macleayi (Castelnau, 1878)

Family:                                    AMBASSIDAE

Description:  size, colour :   A perch shaped fish that is not quite as clear as other glassfishes but has a dark pattern around the scales.  The males in good breeding condition will have mauve or red and tellow tinge to their fins.   It grows to 100 mm but more commonly found 70 mm.

Habit:  A schooling species, generalyy found in deeper billabongs and slower parts of deeper rivers adjacent snags and vegetation belts.

Breeding:  It is an egg scatterer,  depositing eggs on the bottom or in dense vegetation.  The eggs are left to hatch on their own once laid.   There is no parental egg minding or fry raising activity once eggs are laid.

Reticulated Glassfish

Male Reticulated Glassfish showing nice colour

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Diet:  consists of small fish, small crustaceans and aquatic insects

Distribution:

Reticulted Glassfish Distribution map

Reticulted Glassfish Distribution map

 

 

 

 

 

 

 

 

 

Aquarium notes:  Relatively easy to keep, not too fussy about water quality.   It grows to 100 mm so a larger aquarium is advised, one that is about 90cm X 45cm X 45cm would be suitable for about 8 or ten.  They school when conditions for schooling are created.   It is difficult to breed in the aquarium but relatively easy to induce to spawn in a pond of 3 to 5 tons.  Will take a prepared diet of minced and prawns and fish fillet.   Also takes aquaculture crumble. Tank companions, It would be a good community aquarium fish with all the rainbows and native catfishes and other larger natives that grow over 100 mm.  It should not be trusted with small blue-eyes or small shrimps.

IMG_1402a

Reticulated Glassfish fry a few days old.

 

 

 

 

 

 

 

 

The units on the eyepiece are 2.5 units to the mm, so the fry is a bit over 5 mm long.

 

References:

Allen, Midgely and Allen,  2002, “Fresh water Fishes of Australia

ANGFA Data Base       http://db.angfa.org.au/display.php?tbl=fish&id=112

 

Jun 292013
 

Dinosaur fertilisers explanation.

 

Dinosaur spit is a ten percent solution of glutardaldehyde, a carbon compound usually used as a disinfectant in hospitals and piggeries however in small doses appears to kill single celled animals for a while then break down to carbon that becomes available for plants thus a two level plant growing assistant. An attack on algae and carbon for plant growth.

Dinosaur Spit LabelFrequently Asked Questions about Dinosaur Spit

Dinosaur dung is a mixture of blood and bone fertiliser with terra cotta clay and has some phosphate, it is placed under or near plants and supplies organic fertiliser as well as increasing the cation exchange capacity of the soil. (look up “cation exchange plant growth” on Wiki if you want an explanation).  Put two or three pellets around your big plants and dont do it again till you notice the leaves getting a little smaller or other plants slow down.

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Frequently Asked Questions about Dinosaur Dung

Q1.  How big is a dinosaur dung pellet.   A1.  A dung pellet is cylindrical and approximately 18mm tall and 18mm diameter.

Q2.  How long does dinosaur dung last in the planted aquarium.  A2.  The clay will last for ever, the blood and bone fertiliser will slowly be removed from the clay by plants may last up to 3 months before it is all used up by the plants.

 
Dinosaur pee is a mineral fertiliser that is a mix of micro and macro fertilisers less phosphate because phosphate and iron don’t go together. It supplies all the fertiliser needs except phosphorus which gets added in fish food and in the blood and bone from the Dinosaur Dung.

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Frequently Asked Questions about Dinosaur Pee

 

The three different fertilisers are meant to be used together for the average sort of planted aquarium with water plants that has enough light and water movement to support plants growth. If you have a lamp that belts out heaps of light and want exceptional fast plant growth I suggest you go for the EI method.  Aquagreen can supply most of the mineral fertilisers to make up your own mix.

 

 

 

Jun 282013
 

Freshwater Plankton

The term plankton, singular plankter are any organisms live in the water column and are incapable of swimming against a current (from wkwipedia).

The number of species in the marine environment is huge and when we talk about plankton we usually think of the open ocean and the large marine creatures that eat plamnkton, whales and whale sharks come to mind.  However there are plenty of critters in the freshwaters that are generally along with bacteria the start of the food chain.

Plankton comes as phytoplankton, plant plankton and zooplankton, animal plankton.  The creatures in the freshwater billabongs and non permanent waters of the NT tropics are geared to go through many generations during the wet season and as we go further into the inland they are geared to go through their life cycle when water is available, sometimes many years apart.

When I started to try different ways to grow local native plants I would bring home a bit of black soil to try different growing media.  I noticed many small creatures turning up in the ponds and blooms of different colour green after adding fertilisers.

The Aquaculture Industry has pond mechanics who have a relationship with plasnkton, the success of a pond aquaculture operation, particularly prawns operation usually depends on the success of the plankton culture.

Breeding difficult fish in captivity is often dependent on having the plankton that stimulates the fish larvae to take its first meal.  I remember a conversation with Glenn Schipp about a particular type copepod from Darwin Harbour as the critter that made their Golden Snapper take their first feeds.  The attempts to breed small fish that have not been bred in captivity before may depend on the type of plankton offered as a first food to fry.

 

Identifying the different types of freshwater plankton is difficult.  There are some good guides and information on the www as well as good books that I will list below in the references section.

Paramecium

Rotifers

Cyclops

Side view of Cyclops

Side view of Cyclops

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Moina and Daphnia

Moina from Howard River

Moina from Howard River

Howard_River_Plankton_36a

Clamshrimps

Clamshrimp from Howard River

Clamshrimp from Howard River

 

 

Desert Plankton

Algae

Pictures are coming.

Growing plankton in a pond is very enjoyable.  The Scientists at the Darwin Aquaculture Centre gave me a schedule for growing plankton that went over 35 days.  I modified it down to 30 days so I can start my ponds off at the first of the month so I always know what day we are up to just by looking at the calender.  It is the best way to feed your pond and aquarium Fish.

Plankton Culture guide below is a rough schedule for making a plankton culture.

 

FERTILISATION SCHEDULE FOR PLANKTON CULTURE

Fill pond make sure hardness and alkalinity are each over 50 ppm

Increase alkalinity with potassium bicarbonate 20 gm per 1000 litres to increase 10 ppm.

Increase hardness with, dolomite lime or a mixture of 1/1 epsom salts with calcium chloride or 1/1 Lime and magnesium sulphate, 20 gm  per 1000 litres will raise hardness approx 10 ppm.

Day 1         add inorganic fertiliser ((currently I use Aquasol at 2 ppm) (Optional – add some dry soil from a nearby dry stream or billabong)

Day 3, add organic fertiliser  @  50 ppm (only add 6 ppm if fish present)

Day 12, add inorganic fertiliser as day 1

Day 14  start harvesting plankton or stock with fish

Day 17         add organic fertiliser @ 6 ppm

Day 22         add inorganic fertiliser as per day 1

Day 24         add organic fertiliser @ 6 ppm

Day 27         add organic fertiliser @ 6 ppm

Day 31          add organic fertiliser @ 6 ppm

 

 

This is not a strict schedule and may need to be modified depending on the following factors:

 

1.         A sicce depth of less than 40 cm will negate the need for later inorganic fertiliser.   A sicce depth of over 70 cm will require an addition of fertiliser. (try  2ppm inorganic)

2.         An occurrence of filament algae will negate the need for later inorganic fertiliser.

3.         Low oxygen levels will negate the need for later applications of organic fertiliser

4.         For a pond with life that is established omit the 50 ppm organic fert addition and replace with 6 ppm organic on day three.

 

References and further reading

Boyd, 1995, “Bottom Soils, Sediment, and Pond Aquaculture“.

Hoff & Snell, 1987,  “Plankton Culture Manual

Jun 272013
 
Bruce's Pond

Bruce’s Pond

Pond Servicing Introduction

The Darwin water supply is collected from Darwin River Dam area with additional waters from the Girraween bore field.  The water is soft and low in total dissolved solids which means there is little carbonate and bicarbonate as well as low in calcium and magnesium.     It is also a reason that some attempts at water gardening in and around Darwin do not go as well as they could.  If  bore water is used, the ground water should be tested and management practises revised to suit the water quality obtained from the bore.  Hard alkaline water has some different issues managed in a different manner to the Darwin water supply.

Clem's Pond

Clem’s Pond

Water Temperature

Water gardening in the tropics requires that the warmer conditions in the water be managed by creating shade over 50% of the waters surface and up to 70% if possible.  This shade is provided by water plants, by taller reeds, nearby trees and buildings.   It is necessary to prevent the water to become too hot.   Temperature is the first of the major water quality parameters to control.   A high temperature can be responsible for lower dissolved oxygen levels and problems for fish and other creatures that have gills.  The shade of the nearby trees and establishing water plants will be sufficient to keep the water cool enough during the warmer months.  It is suggested that water be kept below 30 degrees celsius.

 

Robin's Pond

Robin’s Pond

Carbonate Hardness

The low dissolved solids in Darwin tap water will create unstable conditions in the water with large swings in pH caused by lack of buffering capacity in the water.   Buffering capacity is also known as temporary hardness, carbonate hardness, acid binding capacity or alkalinity.  We will call it carbonate hardness and it is a measurement of the carbonates and bicarbonates expressed as parts per million.  We will use the term Carbonate Hardness for our purposes.  It is also known as KH.  Carbonate hardness manipulation will also be the way which we control pH swings.

Carbonate hardness is one of the most important water quality measurements for submerged plant growth.   The tendency is for it to fall from plant take up of carbon and wet season dilution.  By adding 20 grams of either Potassium bicarbonate (preferred) or Sodium bicarbonate per ton (1000 litres) the KH will go up approx 10ppm.

General Hardness

Another part of the dissolved solids in water is the two most common minerals in water, this caused what is termed hardness.  The term was derived from waters resistance to lather when soap is used.    This is a measurement of the amount of calcium and magnesium in the water.   The term used in the aquarium and pond trade is General Hardness also known as GH.   It along with carbonate hardness are measured with reagent test kits.    General hardness in cement ponds is generally buffered by the lime in the cement.  However it is monitored and corrected where necessary.

General hardness can be increased by the addition of Dolomite Lime or a 50/50 mix of Calcium carbonate and magnesium sulphate or a 50/50 mix of Calcium chloride and magnesium sulphate, the latter mix will have an immediate effect on GH and the Dolomite lime will take quite some time to dissolve.

 

Algae Control

Algae in a pond is easily controlled.  When there is a good coverage of healthy growing plants using the nutrients the algae will be out competed.  There are other ways to control algae, Darwin waterways has a number of algae eaters and these can be introduced to the pond.  The Atyiid Shrimp we call Darwin Algae Shrimp, Caridina sp. An undescribed species that has a love of filament algae, these can be introduced in large numbers.   They are produced in Howard Springs under aquaculture license for the aquarium and pond trade.  There is more information here –

http://www.aquagreen.com.au/plant_data/Caridina_sp_NTnilotica.html

There are other native species suitable for algae control.  The snail known as Waterhouse Snail, Notopala waterhousei, eats blue-green algae and has the ability to siphon green water filtering the green and eating it.   There is more information about this snail here, it is a NT native-

http://www.aquagreen.com.au/plant_data/Notopala_waterhousei.html

The small forage fish called Flyspeck hardyhead, Craterocephalus stercusmuscarem, will eat filament algae and are best introduced in schools of more than 20.

 

Fish and Turtles

The traditional pond fish are goldfish or Koi Carp.   However many people in the top end like to put Barramundi or Red Claw Yabbies in ponds.  Redclaw are herbivores and the first thing they eat are the water lilies.  The addition of Barramundi will mean that most other small species will be hunted until they are all gone.  There are other species that are a bit bigger an will be left alone.   If more marginal plants are added then there will be more shelter and it will be possible to have more smaller forage species.

People usually put goldfish in ponds, however there are several native pond fish although not as colourful as goldfish will be a very interesting display and will interact with visitors.  Common Archerfish are curious and can be trained to spit water at visitors.  Tarpon are very visible and make a good display.  These species usually do not do well in soft Darwin tap water ponds unless the water quality, hardness, carbonate hardness are kept higher.

A suggested list of native fishes suitable for these ponds –

Delicate Blue-eye                             Pseudomugil tenellus

Black-banded Rainbowfish                  Melanotaenia nigrans

Banded Rainbowfish                           Melanotaenia trifasciata

Flyspecked Hardyhead                  Craterocephalus stercusmuscarem

Common Archerfish                           Toxetes chatareus

Black Catfish                                    Neosilurus ater

Tarpon                                             Megalops cyprinoides

Barramundi                                    Lates calcarifer

There are several species of freshwater turtle available to use as ornamental species.   The most common two available around the top end are Yellow-Faced Emydura Turtle and the Northern Snake-neck Turtle.  The long necked turtle will hunt fish but not climb.  The shortnecked yellowfaced turtle wont catch fish as much but will climb.  There are several Turtle breeders around the rural area who’s advice can be sought as to the best local species to suit the pond location and construction.  Tonia Thompson is one breeder and may be able to advise the best species to suit that particular pond.  If the area can be fenced back from the pond then perhaps a freshwater crocodile could be considered as an inhabitant.

Filter Management

A swimming pool pressurised sand filter can be used and should be operated all the time, 24 hours a day, if it is operated for a few hours at a time the biological content inside the filter will foul and when the filter is next turned on a filter full of foul toxic water will be sent into the pond.      A biofilter needs oxygenated water flowing over the bed to be constant otherwise the aerobic beneficial bacteria die and foul the water.  There are low electricity consumption pumps that can be run continuously without breaking the bank.   There are low profile purpose built pond filters made for these special pumps.

Wildlife Drowning

If the edges of the pond are steep it prevents smaller animals from escaping and they will eventually tire and drown.  If no turtles are to be kept it is recommended that some structure for animals to climb out be provided.  If turtles are to be kept perhaps such a structure can be provided so animals in the water can gain access to an island.

Water plants

Water lilies need occasional addition of a slow release fertiliser such as Monsoon Tablets from Tropigro or Dinosaur Dung from Aquagreen.  A selection of marginal plants can be added if it is desired.  These marginals will be OK planted along the shallower ledges and will form habitat for smaller forage fishes to hide from Barramundi or other larger species.  A selection of marginal plants is available from Territory Exotics.

As the plants grow over the pond surface the algae will be a dim memory.  The best control for pond is to have a balance of life forms that will achieve the objectives required.  Removal of leaves that blow in a couple of times a year will help keep the water quality near the desired levels.

 

Pond Security

A pond should have a place where wet season water can over flow without taking the fish and plants away.   It is not desirable to let water plants or fish get into the drains or any natural waterways.  Water plants that become weeds are harder to eradicate thean ordinary weeds as are feral fish.  There are guppies, platies and swordtail fish from Venezuala, South America in the local creeks and drains around Darwin from people who have let their ponds overflow without a sieve or barrier to stop escapees.

Conclusion

The management of ponds in the tropics is slightly different to maintaining a pond in a more temperate climate.  Regular attention to water quality and plant fertilisers with the occasional clean out of organic waste will help maintain a pond that will be pleasing spectacle for visitors and the owners.

Recommendations

That the carbonate hardness be maintained about 60 to 80 ppm via above mentioned methods.  This will keep pH about 7.2 to 7.9 approximately.

That the hardness be maintained between 60 ppm and 200 ppm using the above mentioned methods.

That water quality tests and records be kept with a monthly frequency keeping records of the functions performed.

That water plants be fertilised when needed, usually water lily leaves will be a good indicator, each new leaf should be slightly bigger than the last or the same size.  If the leaves are smaller it is time to fertilise the plants.

That excess organic material be removed each month.  Leaves and other material will blow into the pond.

That the filter be changed down to a low electricity consumption model to run 24/7.

 

Jun 262013
 

 

Introduction

Andrew South helped me come up with some information about managing Darwin Tap water for Aquaponics.  The info will help with other water supplies. Aquaponics is the use of a fish culture pond where the resulting nutrient waste from the fish is used as an hydroponics solution to grow vegetables or ornamental plants.  It is said to be the most efficient use of water to produce 100 kg of food.

Darwin has soft tap water with chlorine disinfectant.  It is good quality but soft.  Its use in fish ponds and aquaria requires the addition of some compounds to increase hardness and carbonate hardness.

Converting tap water to culture water

Water quality measurement can be divided into two parts.  Raw water or make-up water before the influence of your fish and plants, the parts that you measure are temperature, pH, KH and GH (salinity if you have a bore near the beach or Alice Springs).  You can measure this just out of the tap then after putting an air stone in a sample for 30 minutes to degas CO2 which will change pH. This is important in harder water used in recirculating systems (your aquaponics is a recirculating system).

If using town water supply it is important not to add more than about 20% to an established system otherwise water authority additions such as chlorine may kill the plants and fish in the system.

The Power and Water Authority will have water quality information for the local supply.  It is also important to know what type of chlorine treatment is carried out on the water supply.

There are sections in the Government web site where a registered bore has its original specifications recorded, depth and water quality.

A 2004 report on NT Water Supply.

System Water

After water is influenced by life forms it takes on ammonia, ammonium, nitrite and nitrate, phosphate, potassium and other plant nutrients as well as a higher bacteria load.  Most are innocuous or have little effect on plant growth unless they are in over supply or short supply such as some of the micronutrients especially iron.

The nitrogen cycle is the most important part of this system and has measuring kits available to monitor levels.  Bacteria in the grow beds convert fish ammoina/ammonium to nitrite and nitrate.  The level is managed by balancing the amount of fish with the plant growth.  It can be thought of as a nutrient bank where deposits (fish food and supplements such as potassium and micronutrients) equal withdrawals such as harvesting plant material so there is always plenty of growth to take up nutrients produced by the fish waste.

These are Ammonium, nitrite and nitrate tests. pH tests will indicate lower if nitrate is being converted to nitric acid a byproduct of nitrification.  The most dangerous nutrient is high pH is ammonia.  It is part of total ammonium and the percentage of ammonia (NH3) depends on pH and temperature.  There is a calculator table here – http://www.cnykoi.com/calculators/calcnh3c.asp

A high pH can be very dangerous to fish because it increases the toxic part of the Ammonium/ammonia relationship.  A high pH causes more of the total to be in the more toxic ammonia form, lower pH makes more ammonium which is less toxic.  Take measurements and make adjustments if necessary.

Carbonate hardness (KH, Alaklinity)

Measures the bicarbonate and carbonate dissolved in water.  (Not to be confused with total alkalinity, this is a different measurement)
Measured with a test kit (I like Aquasonics products, inexpensive and reliable).  The desirable level is over 50 ppm or three German degrees if you have a German Aquarium test kit.  It is probably the most important water quality measurement because it is the way we fix pH problems.  The Alkalinity level will gradually reduce over time as the plants will take up the carbon and KH will need readjusting upwards.

Make adjustment by adding 20 grams of potassium bicarbonate or sodium bicarbonate per ton (1000 litres) to increase the measurement by 10ppm or half a German Degree.

General hardness (GH or hardness or total hardness)

Is a measurement of the carbonates of calcium and magnesium dissolved in the water.   It adds these two important plant minerals and increases ionic strength which keeps fish more comfortable and helps with their osmoregulation (look up osmoregulation and fish stress).   It is best kept over 50 ppm and can be higher without much problem.  Hardness will drop over time because plants will take up calcium and magnesium and GH will need readjusting upwards.

Add 10 grams of Magnesium sulphate and 10 grams of calcium carbonate per ton of water to raise the GH reading 10 ppm.  Mix these two separately and dose them.  This will give you a calcium to magnesium ratio of about 4 to 1.   Aquagreen mixes 7 parts Magnesium sulphate, 10 parts Potassium sulphate and 6 parts Calcium chloride and called it GH Booster, it is added at 20 grams to the ton of water which will raise general hardness by 7.2 ppm.

The best thing you can do is learn the plant nutrient deficiency signs and learn about your fish and what water quality suits them.   Smell the plant substrate and water occasionally, both should have a nice earthy smell.

The fish will provide most of the nutrients, however there may sometimes be an advantage adding potassium and micronutrients to supplement fish poo.   Aquagreen manufactures a fertiliser that is designed for plants that are kept with fish.

http://www.aquagreen.com.au/plant_data/Dinosaur_Pee.html

Dose between 50 and 100 ml of Dinosaur Pee per ton per week depending on any plant nutrient deficiency signs.

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Barramundi are available from:    Aquagreen  –  http://www.aquagreen.com.au/plant_data/Lates_calcarifer.html

Tropical Veggies from weekend markets and other Aquaponics enthusiasts.

Jun 242013
 

On 4 April 09 the 4 x 2 x 2 photographic aquarium was set up to photograph Mariana’s Hardyhead. I am not quite sure where the Wildlife Park collected them but it was probably the upper South Alligator River or the East Alligator River in the top end of the Northern Territory.

Mariana\'s Hardyhead

It is only the first few minutes in the aquarium and they have a couple of split fins from being caught from their pond. In a few days or a week they will settle in and be more relaxed and hopefully more colour will show.

Jun 242013
 

Description

A tall slender rush with a dark green/grey cylindrical stem. It has a creeping ryyzome and a small single brown oval shaped seed pod near the spike end.

Lepironia articulata

Lepironia articulata

Lepironia articulata

Lepironia articulata

Lepironia articulata

Photos – Dave Wilson

Distribution
Taiwan, Magagascar, Fiji, in Australia it occurs in the NT, Qld and WA.

Habit
In the NT it grows in shallow water margins of still water.

Cultivation
A potting mix with some organic matter and not too much nutrient. Suggest one part laterite soil, one part peat, one part river sand mixed and covered with a couple of inches of sand grown in shallow water.

Uses
Would make an attractive rush for ornamental ponds and has been put forward as a plant that may be used in a constructed wetland to prevent erosion and take up nutrients. May also be useful as a filter plant in a natural swimming pool.

References
Cowie, Short, Osterkamp-Madsen (2000) “Floodplain Flora”
Stevens, Dowling (2002) “Wetland Plants of Queensland”