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 |
