Akysis longifilis Ng,
2006 |
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”.
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 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.
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.
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.
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.
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.
|
| Feeding |
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).
|
| Photo
Credits |
Steve Grant and Heok Hee Ng |
