he first factsheet of 2021, which we all hope will
be a lot better than the previous year provides me
with a memory of way back in April 2017 when I first
embarked on a collecting trip to the Rio Madre De
Dios area of Peru with the Eco Travel Company, Go
Wild Peru, with the owner Ian Fuller from CorydorasWorld.com
along with my companions, U.K. aquarists Steven Grant
(Catfishes of the World), Richard Smith, and Jamie
Horne. This will maybe push me to write a further
article on this special trip sometime in the future.
wild caught specimen
of the most abundant catfish species we came across
on our 14 day trip was our factsheet of the month
subject, the "Shrimp Catfish", Imparfinis
stictonotus. Thismember of the Heptapteridae family is known
from its type locality Todos Santos, Rio Chapare,
in Bolivia and the area of the Madeira River basin
which is close and covers the south eastern parts
of Peru. This species is very like Imparfinis
pseudonemacheir and I'm yet to be convinced that
this is not the same species although the type locality
for this is further north in Venezuela and covers
and Ucayali River basins.
As far as I am aware Imparfinis
could end up as a synoynm of
in the future. The image
above shows a freshly caught specimen from near the
city of Puerto Maldonado and below an aquarium specimen
showing a dark pattern, but the wild caught specimen
could be showing a fright pattern.
The map below
shows the area of capture in Peru and the type locality
in Bolivia. A note on the water parameters from this
location was a high p.H. of 8.2 and a temperature
of 25.8C (78.4F) which considering the large area
covered for this species indicates that it is very
hardy little catfish. We found a lot of specimens
on the sides under vegetation in small streams with
every sweep of our nets.
family was diagnosed by osteological characters by
Bockmann 1998 which are not easily observed externally.
The whole family can be found in a vast area of South
America in the coastal drainages of Guineas, Amazon,
Orinoco, Sáo Francisco, and San Juan basins,
Paraná, Uruguay, and Paraguay basins; and along
eastern Brazilian coastal basins. The genus name of
Imparfinis ; Latin,
impar = unequal + Greek, finis, pinna = wing, fin
refers to the longer top lobe
in the caudal fin which you can see in the image above.
This genera has
22 described species recorded with the types species
being Imparfinis piperatus Eigenmann &
Norris, 1900, with one (I. lineatus) in Central
America. Most of them don't grow too big and can be
housed with most fish as long as they are not too
small with the danger of them being eaten.
Location near Puerto
Distrbution:Ucayali, Mamoré/Madeira and Paraguay
River basins. Type Locality:
Todos Santos, Rio Chapare, Bolivia.
The Madeira River is a major
waterway in South America. It is estimated to be
1,450 km (900 mi) in length, while the Madeira-Mamoré
is estimated near 3,250 km (2,020 mi) or 3380
km in length depending on the measuring party and
their methods. The Madeira is the biggest tributary
of the Amazon, accounting for about 15% of the water
in the basin. A map from Emanuel Bowen in 1747,
held by the David Rumsey Map Collection, refers
to the Madeira by the pre-colonial, indigenous name
Ucayali, Mamoré/Madeira and Paraguay River
basins. Type locality: Todos Santos,
Rio Chapare, Bolivia.
Genera description: Moderately
elongate body, oval in cross section through the dorsal
fin origin; snout convex in dorsal view; mouth subterminal;
eye of medium size, dorsolateral, with free margin;
premaxillary tooth plate wide, not bearing projection
at posterolateral angle; maxillary barbel moderately
long its extremity usually reaching the end of the
pectoral fin. Pectoral fins usually with 8-10 branched
rays; first dorsal fin ray (spinelet) absent. Anal
fin short having 11-15 rays; caudal fin deeply forked.
Lateral line usually continues to caudal peduncle.
Brown to greyish, with 7 transverse
dark bars on back; one immediately posterier to head,
one in front of dorsal fin origin, one on postereir
half of dorsal fin base, one between dorsal fin base
and adipose fin base, one on adipose fin origin, one
on adipose fin end and one on base of procurrent rays
of caudal fin. A lateral stripe is normally present.
Care & Compatibility
Peaceful towards conspecifics
but territorial with its own kind. Provide a moderate
sized aquarium with hiding places such as bogwood,
rockwork and plants. A good water flow is recommended
with good aeration and filtration. They tend to bury
themselves in the substrate so sand on the bottom
would be the substrate of choice.
are externally fertilising and are not known to practice
parental care. Amaral et al. (1998) described reproductive
females of a member of the Heptaperidae family, namely
the species Pimelodella pappenheimi which
was burying in the clay palsades of the sediments
of a small coastal stream in southern Brazil, a behavior
adaptation to protect the offspring from being washed
is not present or scarcely developed in heptapterids.
Juveniles of most species are miniature replicas of
the adults. There are few data on the reproductive
cycle of heptapterids, probably due to its reduced
importance in commercial fisheries and aquarium imports.
In their natural habitat they
will be found solitary and active during the night
hunting for insect larvae turning over the sand/gravel
substrate in seach of prey. In the aquarium they can
be fed, live, frozen and flake foods.
Tail Caudal peduncle: The narrow part
of a fish's body to which the caudal or tail fin is
attached. Dorsal fin:The
primary rayed fin(s) on top of the body. Lateral line: A sensory line, along
the sides of the body. Maxillary barbels: Pertaining to
the upper jaw. (maxillary barbels). Pectoral: The paired fins just behind
Imparfinis:Latin, impar = unequal
+ Greek, finis, pinna = wing, fin (Pertaining to the
longer top lobe of the caudal fin).
C.J. Jr., 2007. Checklist of catfishes, recent
and fossil (Osteichthyes: Siluriformes), and catalogue
of siluriform primary types. Zootaxa 1418:1-628.
Froese, R. and D. Pauly. Editors. 2009. FishBase.
World Wide Web electronic publication. www.fishbase.org,
version (05/2011). Grant, Steven.
pers comm. Sleen, van der Peter and Albert, S. James;
Field guide of the Amazon, Orinoco & Guianas.
Princeton University Press, Princeton and Oxford.