This factsheet for the month
of December 2007 has been complied by Catfish author
and regular ScotCat contributor Steve Grant and centres
on one of his favourite catfish familes, Akysidae,
aka "The Asian Stream Catfishes". His subject
from this family is a most beautiful species, Akysis
longifilis. I will now hand you over to Steve.
his
beautiful but secretive catfish has been available
over the last few years in a select few aquarist shops.
The name initially given to the fish initially was
Akysis pictus Günther, 1883, which has
a similar colour and pattern, and is also from the
region of Myanmar that these fish were being caught.
However, it wasn’t until 2006 that the species
was described as a new one by Heok Hee Ng, and the
differences between it and A. pictus were
pointed out. To date I haven’t seen a live
A. pictus, but Ng states “Akysis longifilis
possesses two distinct light saddle-shaped spots on
the upper surfaces of the postdorsal region, while
A. pictus possesses a very long light saddle-shaped
spot in the same region”.
Akysis
longifilis
+ Akysis prashadi
The type specimens
of A. longifilis were caught in Pyu stream,
which is a tributary of the Sittang River, 18°29'N,
96°26'E, Pyu township, Bago division, Myanmar.
The number of
described species of Akysis has grown considerably
over the last few years, primarily because of the
work of Heok Hee Ng and others. The number of species
imported for the hobby has also grown and some species
are very similar to others, sometimes making identification
difficult for the untrained eye. However, although
it is similar to a few described species thankfully
it is easily differentiated from those we currently
see in the hobby. The easiest method of identification
is its pattern (see images above). Please note however
that on my image, the marks on the body are not showing
up as dark as they normally do.
Akysis
longifilis
Akysis
are easy to keep for any decent fishkeeper. The fish
in my images are owned by my friend Roy Blackburn.
His fish are kept in small tanks (30cm wide x 20cm
high x 30cm deep) with a sand bottom, small pipes,
and caves. They will either bury themselves in the
sand or hide in caves and pipes. They are not usually
active during the day but will spring to action and
eat voraciously and crazily if food is put in the
tank.
All
in all these are beautiful little catfish and one
I can recommend.
Common
Name:
None
Synonyms:
None
Family:
Akysidae
Subfamily:
Akysinae
Distribution:
Asia:
Sittang River drainage, southern Myanmar (Burma).
Size:
5.5cm (2¼ins)
Temp:
18-23°C
(63-73°F)
p.H.
6.7-7.2.
Characteristics
Dorsal fin with one hard spine
and 3-5 rays; Caudal fin 1 principal ray and 6 rays
on each lobe; Anal fin with 3 simple rays and 5-6
branched rays; Ventral fin with one simple ray and
5 branched rays; Pectoral fin with 1 spine and 6 branched
rays. Four pairs of barbels; lateral line complete.
Colouration
Dorsal surface and sides
of head ranging from a sandy to golden tan colour,
with few darker brown spots randomly scattered throughout.
Dorsal surface and sides of body dark brown. Belly,
chest and ventral surfaces of head and body light
brown. Dorsal half of body with two elongate saddle-shaped
light to dark brown or even blackish spots: first
on body at anterior three-quarters of adipose-fin
base, second more elongate and between posterior
fifth of adipose-fin base and caudal flexure. Ventral
half of body with two similar saddle-shaped, light
to dark brown or even blackish spots: first between
anal and pelvic fins and second between posterior
base of anal fin and caudal flexure. Anterior ventral
spot largely coalescent with light brown coloration
of ventral surfaces. Proximal two thirds of dorsal
fin chocolate brown. Anal and pelvic fins hyaline
with very few brown spots forming indistinct transverse
band through middle of fin. Proximal half of pectoral
fin with reticulate brown band; rest of fin hyaline.
Caudal fin chocolate brown with distal one third
of both upper and lower lobes with large, mostly
hyaline spot (with scattered melanophores). Adipose
fin dark greyish brown, except where lighter brown
saddles-shaped spots on body run through fin. Barbels
light brown, maxillary pair sometimes with few brown
rings proximally.
Aquarium
Care & Compatibility
We have found them to generally
be a peaceful catfish, including amongst themselves.
Having said this I wouldn’t necessarily trust
them with anything small enough to fit in their mouths.
Reproduction
Although some
fishkeepers have found eggs, I am not aware of any
successful hatching and rearing of fry of this species.
Sexual
differences
Males appear longer
and narrower in the body to the bulkier females, although
even males can get large if fed too much.
Diet
They will eat bloodworm, chopped
earthworms, whiteworm, daphnia, and sinking pellets
(although they seem to prefer live or frozen food).
Glossary
of Terms
Proximal:
toward the center of the body; the region, the border
or the point adjacent to the place of attachment of
a projection or appendage; the opposite of distal. Hyaline: Clear.
Etymology
longifilis:
From the Latin longus, meaning long, and filum, meaning
thread, in reference to the long barbels of this species.
References
Ng, H.
H., 2006.Akysis
longifilis, a new species of catfish (Teleostei: Akysidae)
from Myanmar. Zootaxa 1150: 19-30 (2006). Hillstream Catfish
website (for Ph and temp ranges).
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