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Paretroplus nourissati

P nourissati
Paretroplus nourissati
Image Credit: wikipedia

Introduction



Paretroplus nourissati is a medium sized fish in its genus and has a standard length of 4.0" and total length of 6.0".
It is found in Amboaboa and Mangarahara river basins in Northeastern Madagascar.


Taxonomy

(Click for details of Cichlid taxonomy)

Paretroplus nourissati was first described by Allgayer in 1998. The genus Paretroplus is further divided several groups called clades.
P nourissati belongs to clade consisting of fish which are comparatively elongate and primarily live in rivers and swift flowing waters.
The other members of this clade are P. damii, P. tsimoly, P. lamenabe, P. loisellei.
The genus name Paretroplus comes from the Greek 'para' meaning 'on the side of'; in taxonomy it is commonly used in generic names to express similarity or relatedness.
Hence the genus name literally means 'next to Etroplus' and signifies the close relationship these two genus have.
The species is named in honor of the honor of the French aquarist, naturalist, traveler Jean-Claude Nourissat, who with Patrick de Rham discovered the species in 1991.



Description

Paretroplus nourissati is a shallow bodied and relatively elongate of its clade.
It has a standard length of 4.0" and a body depth of 40.5 % of SL.
Head is pointed, head length is 34.7% of SL and width is 17.8 % of SL.
Snout is 46.7 % of Head length and is moderately curved.
Predorsal profile is moderately curved and is 45.9 % of SL.
A pointed head with moderately curved snout and predorsal contour gives the fish a beaky appearance when viewed from side.
Dorsal body outline is slightly curved,
Ventral(lower) outline mostly straight (except posteriorly).
Caudal peduncle is short, deep, and laterally compressed.
Total vertebral count is 29 or 31, 13-14 vertebra on body (pre caudal) and 16-17 on tail.

Lower and upper jaws are similar (isognathous). There is a single row of thin, flat, single cusp teeth in both upper and lower jaws.
Teeth are laterally expanded, flattened at crown. In upper jaw, tooth on either side of pre maxillary symphysial are greatly enlarged, other teeth graded in size laterally.
Lower-jaw teeth at symphysial are not enlarged, but reduced in size compared to adjacent lateral teeth, presumably to accommodate enlarged upper symphysial teeth.
Teeth in upper jaw number six to nine on each side, and total 13–16.
Teeth in lower jaw number six to seven on each side, and total 13–16.
Teeth in both upper and lower jaws are frequently irregularly spaced and graded in size laterally.
Like all cichlids, P. nourissati have pharyngeal teeth.
Upper and lower pharyngeal tooth plates are well developed with strong teeth.

Body is covered with large, overlapping, cycloid scales.
Flank scales on back side are thin, lack circuli(rings) , un ossified and form a flexible 'flap'.
Dorsal and Anal fin bases have well-developed ridges of scales.
Pelvic auxiliary scale are present and well developed.
Lateral-line contains 35–39 scales.
Chest scales are markedly reduced in size and embedded.
Scales along ventral midline are smallest.
There are four to five rows of scales on cheek. Opercle, subopercle, and interopercle scaled.
Snout, and region near eyes does not have any scales.
Scales on caudal fin are small in size and extending posteriorly about 3/4 length of fin on dorsal and ventral lobes, and 1/3 length of fin medially.
Dorsal fin is placed vertically above pectoral fins base and has XIV–XVI spines, 12–15 soft rays.
Soft Dorsal fin is weakly pointed.
Anal fin has VII –VIII spines, 10 –13 soft rays.
Soft anal fin is weakly pointed.
Caudal fin is concavely curved but not forked ( emarginate) , upper and lower lobes are broad and more-or-less rounded.
Pectoral fin is broad and rounded at the end .
Pelvic fin extends to about level of anal-fin origin.



Distribution & Habitat

Paretroplus nourissati known range is restricted, it is found only in Amboaboa and Mangarahara rivers near their confluence, which is in the vicinity of the town of Mandritsara in northeastern Madagascar.
The species is also reported to occur in neighboring lakes, located a few kilometers from the confluence of the Mangarahara and Amboaboa rivers.
The Amboaboa River is a tributary of the Mangarahara River, which itself is a moderately sized left-bank tributary of the extensive westward flowing Sofia drainage.
Paretroplus nourissati co-occurs in these rivers with P. gymnopreopercularis; neither species has been collected to date from the Sofia River proper.
Ichthyological surveys in this remote region of Madagascar have not been extensive and P. nourissati could potentially be more widespread in distribution.
Although not widespread in distribution, in the mid-1990s P. Nourissati was still relatively common within its limited range in the Mangarahara and Amboaboa rivers.
Nevertheless, in consideration of its very restricted distribution, P. nourissati would seem to be vulnerable to increased fishing pressure and continued habitat degradation.

Unfortunately, de Rham and Nourissat (2004) reported that on their last visit to the region (in 1999) they found the Mangarahara River upstream from its confluence with the Amboaboa River to be completely dry due to the combined effects of a prolonged drought in the region and water diversion to irrigate rice fields year round via an upstream dam.

Subsequent ichthyological surveys of the Amboaboa River found P. nourissati to be abundant in 2004, but greatly reduced in numbers in 2006, possibly as a consequence of the many years of severe drought that the region has experienced (P. Loiselle, personal commun.).

Habitat :
The Amboaboa and Mangarahara rivers near the type locality are shallow, clear (low in turbidity), and the current is swift, with many areas of small cascades and riffles.
These rivers flow over large areas of exposed bedrock, and the substrate is generally rocky, with many exposed boulders, and interspersed with areas of sand.
Paretroplus nourissati frequents shallow, rocky stretches with a swift current and riffles. The species is frequently collected in swift-flowing water only a few inches deep, where it hides under rocks.

Colouration



Base colour of body ranges from pinkish brown, grayish or reddish brown to bright yellowish- orange, orangish-red.
While breeding the colour changes to bright red.
There are two prominent vertical and generally converging (below the lateral midline) dark gray to jet black mid lateral bars.
There are six or seven vertical bars present on flanks. Apart from two prominent mid lateral bars, representing the second and third or third and fourth bars in series, remaining bars are generally faint, although those on posterior region of flank easily visible.
Fin coloration ranges from gray, pinkish brown, or reddish brown and similar to base body coloration in non breeding individuals, and solid yellowish orange, orangish red, or bright red in breeding individuals.
Lips, lower cheek, gular region, and belly very pale blue or grey in sexually active individuals.



Conservation Status & Threats



IUCN Red list shows status of Paretroplus nourissati as "Vulnerable".
This species is known from the Sofia river drainage in Madagascar.
Survey of the area has been limited and it is thought likely to be more widespread.
With an estimated extent of occurrence of less than 20,000 km², a fragmented habitat, and a continued decline in habitat due to deforestation, this species is assessed as Vulnerable.
It is also subject to competition and predation from introduced exotic fish species.

Major Threats: Habitat destruction, overfishing, and competition from a number of exotic species, primarily tilapiine cichlids and the Asian snakehead are major threats faced all madagascar Cichlids.



Tank Size and setup:


It is a medium to large size fish.
Given the fact that these cichlids love to live in groups a tank should not be less than 500 liters.

Water Parameters:
These fish live in rivers and large lakes, and need exceptionally clean water. As their diet is rich in proteins the filteration should be very good.

Feeding



It is carnivore and should be given corresponding diet.
Frozen shrimp, mussels, live snails can be give.


Breeding



There are no sexually dimorphic features apparent, but males are larger.
P nourissati are substrate spawner's.
A pair will dig a spot in sand, and lay eggs.
The eggs hatch after one week.



Species Snapshot

Species Card


Particulars Details
Scientific Name Paretroplus nourissati
Common Name Lamena
Genus Paretroplus
Subfamily Etroplinae
Geographical Origin Africa: Endemic to the northwestern part of Madagascar
Diet Carnivore
Gender Differences Mono morphic
Breeding Substrate Spawner
Temperament Aggressive
Con Specific Temperament Aggressive
Water hardness ph range ; 6.5 to 8
Difficulty Level in Aquariums 4


Morphometric Data


Particulars Details
Total Length(inches) 6.00
Standard Length(inches) 4.00

Measurements as % of Total Length


Particulars Details
Body Depth 40.70 %
Head length 34.70 %
Pre Dorsal length 45.90 %
Pre Pectoral length  %
Pre Anal length 62.50 %
Pre Pelvic length 41.60 %
Caudal Peduncle Depth 14.20 %
Caudal Peduncle Length 10.10 %
Fork length  %
Length of Last Dorsal Fin Spine  %
Pectoral Fin Length 20.20 %
Pelvic Fin Length 19.50 %

Measurements as % of Head Length


Particulars Details
Head Width 17.80 %
Snout length 46.70 %
Eye diameter 25.60 %
Pre Orbital Length  %
Inter Orbital Width 28.40 %
Pre Orbital Depth  %



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