Mr. Kevin Webb, who has a near 20 year friendship with Ryedale A.S., is a well
known Yorkshire aquarist whose photographic skills are seen on the pages of aquatic
magazines throughout Europe and who has also contributed such material, in partnership
with David (who writes the articles), to FAMA.
Mogurnda mogurnda - The Most Popular Australian Goby
By David Marshall and Kevin Webb
Written for the March 2003 issue of the Ryedale Reporter, Ryedale Aquarist
Society, England
Aquarticles
BACKGROUND - Researched by David Marshall
General -The genus Mogurnda contains small substrate dwelling
gobies which have shown great boldness, a tolerance to low salinity levels and an ability
to survive at oxygen levels many other fish species would find intolerable in order to
triumph over a variety of natural and man-made water obstacles thus allowing them to
thrive in a variety of freshwater habitats (including boreholes, fast flowing streams and
ponds) throughout Australia and New Guinea.
Scientific Name - Mogurnda mogurnda
Common Names - Northern Purple Spotted Gudgeon, Australian Spotted
Gudgeon, Northern Trout Gudgeon, Chequered Gudgeon.
Size - 170mm - Usually a little smaller in aquaria.
Range - Mogurnda mogurnda is the only member of its genus
with natural populations found in both Australia and New Guinea. Australian populations
range in the northwest across Kimberley and Arnhem Land to the Gulf of Carpentaria
drainage, Cape York and eastwards towards the Mossman River. New Guinea populations are
found in the lower Kikori River system westward to Etna Bay in the Irian Jaya province.
Throughout their natural range these fish can be found in a variety of habitats, where
they make good use of all available cover and eat any animal or plant material they find
edible.
Aquarium Care - Aquarium with a minimum size of 60x40x40cm.
Temperature 25 C. pH 7 to 8. Decor of plant pots, plastic/real plants and variously sized
rocks. Not for the general tropical freshwater community. Have a reputation as 'fin
nippers'. Will eagerly consume all commercial aquarium fish foods. Keep a tight fitting
lid on their aquaria as, when frightened, these fish can jump clear of their home (natural
predator defence).
Reproduction - In the wild pairs spawn during the rainy season,
November to February, with a mature female ripening with eggs to a maximum of 10 times
during this short period of time.
BREEDING - By Kevin Webb
Two pairs of M. mogurnda, approx. 5cm in total body length, were added to an
aquarium of 60x40x40cm. Resident here were a number of Corydoras. Added to the regular
diet of these fish, as a pre-spawning conditioner, were prawns, high protein pellets and
frozen bloodworms.
Roughly 8 weeks later one of the males began to show an increase in blue body
colouration and began to signal a desire to breed (David - another sign to watch for is
the urinogenital area which becomes very pointed). When a female, ripe with eggs,
responded, she chose the glass sides of the aquarium on which to lay a batch of eggs
(young females lay a maximum of 20 eggs with the number rising to 150 for a mature female,
although I would put the figure closer to 200 in some of the spawnings I have witnessed).
The male had followed his mate in close proximity, and upon fertilising these eggs, took
on the parental duties of egg fanning and keeping all other fish, his mate included, away
from the spawning area.
The demersal adhesive eggs are attached, in a cluster of around 50mm in diameter, to
the glass by small threads, and waft in the current like those of the tropical marine
Clownfish.
Reports from the wild suggest that it takes the eggs between 8 and 10 days to hatch,
but I have found that in aquaria they will hatch much quicker than this. On average 5 days
is taken for the eggs to hatch, with 7 days my longest recorded time.
Once the eggs hatch any parental care ceases, and thus you must either remove the
adults or take a risk that only a small number of fry will survive predation etc. As soon
as these particular eggs hatched, they and the resultant fry disappeared very quickly.
Fortunately I was quick to conduct a thorough tank search and managed to rescue a small
number of fry. Two further spawnings quickly followed, with a small number of fry rescued
from each spawning.
Now was the time to experiment, so when two further spawnings occurred I removed the
eggs prior to their hatching, and artificially hatched these. In this way I managed to
raise between 60 to100 fry.
For my next breeding experiment a group of 20, of equal sex, M. mogurnda were
placed into an aquarium of 90x60x40cm. This aquarium was filled with aged aquarium water
(which contained no salt) and kept at a stable temperature of 28 C, DH of 61 and a pH of
7.5. Decor consisted of a variety of aquarium friendly rocks and boulders. Much spawning
activity followed, but once again all eggs were laid directly onto the side glass.
Once the fry have used up their yolk sac they are fed on brine shrimp and quickly grow.
If you come across these particular fish in your local aquarium store they are
interesting little fish to keep.
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