Etroplus maculatus

Introduction

Etroplus maculatus is a small sized fish in the genus, it has a TL(Total length) of 3.2 ".
Etroplus maculatus is found in Southern and western parts of India and Sri Lanka.

Taxonomy

(Click for details of Cichlid taxonomy)

Etroplus maculatus was first described by Bloch in 1795 Chaetodon maculatus.
The genus name is derived from the words 'etron' meaning belly and 'oplon' for arms.
This refers to the spines that are present on the anal fin, i.e the long spinous anal-fin.
The species name is derived from "maculatus" which means spotted.

Description

Shape :-

Body is deep and highly compressed, depth of body is 49 % of SL (Standard length).
Eyes are large and placed laterally, eye diameter is 11.6 % of SL (standard length) .
Mouth is small and terminal .
Teeth are small and fine (villiform) and found in two or three rows in jaw. There are no teeth on palate (roof of mouth).

Dorsal fin is inserted above pectoral fin base, with 18-20 spines and 8-10 soft rays.
The spinous base is longer than soft rayed base.
Soft Dorsal fin is pointed and reached just beyond the caudal fin base.

Anal fin has 12-15 spines and 8-9 soft rays.
Soft Anal fin is pointed and reaches just beyond the caudal fin base.

Pelvic fins are located on thorax and have 15-16 rays.

Caudal fin is concavely curved but not forked (emarginate).

Scales are weakly ctenoid and are of moderate size, they extend to the base of soft dorsal and anal fins. There are 35 scales in longitudinal series.

Lateral line is interrupted as in all cichlids.
The upper lateral line is separated by 5 scales rows from dorsal fin base, and lower lateral line is separated by 19 scales from pelvic fin base.

A remarkable features of this family, is the development of the front part of the gas bladder and corresponding changes to the posterior of the neurocranium(back part of the skull that houses the brain) to create a direct connection between the gas bladder and inner ear .
This feature is not seen in any other Cichlid families.
This allows fish of this genus to have remarkable hearing power.

Distribution & Habitat

Etroplus maculatus maculatus is endemic to India and Sri Lanka.
In India it is found in western part of India from State of Maharashtra through Goa. karnataka and Kerala, Tamilnadu.
In Srl Lanka it is mostly restricted to Western coast extending to North.

Habitat : Etroplus maculatus inhabits coastal lagoons, lower reaches of river and brackish estuaries. It is known as "euryhaline" i.e it lives in both brackish water as well as freshwater.
It is often with seen other cichlids of its genus.

Diet

Etroplus maculatus is omnivorous and has been seen grazing on aufwuchs (hard algae that grows on rocks ) in the wild.
In wild it is often seen "cleaning" parasites and fungus from body of much larger Etroplus suratensis . It is also seen to eat eggs and larvae of E suratensis.
Hence a varied diet with algae is recommended.

Conservation Status & Threats

Etroplus maculatus is listed as “Least Concern ” in “The IUCN Red list of Threatened Species” 2013.2
Etroplus maculatus has been assessed as “Least Concern ” because of its widespread distribution across a wide variety of habitats in almost the entire southern part Indian peninsula and Sri Lanka.
Population of Etroplus maculatus is listed as stable by IUCN.
Major Threats: A major threat to Etroplus maculatus is pollution, habitat destruction, land reclamation, and exploitation for food and commercial interests.
Conservation Actions: Etroplus maculatus is an abundant species across it's range, despite the vast array of threats affecting itself and it's habitat. This could be attributed to it's successful breeding strategy, employing parental care. However, the species might hold on, up to a maximum disturbance threshold, before showing any significant declines in the face of these threats. Hence, more studies and action in the form of legislation and management need to be strengthened for the long term survival of the species.

Tank Size and setup:

A tank of about 200 liters can be set up for these cichlids.
The tank setup should imitate a river flowing stream or river bed, with gravel of multiple size, small rounded boulders, driftwood can be added to simulate roots of trees.

Water Parameters: Etroplus maculatus are a brackish water fish.
A ph range of 8-9 and Gh range from 10-25 can be maintained for these fish.
They are intolerant of nitrates hence a very good filteration is required to keep nitrates very low and good oxygenation in water.

Tank Mates:

Etroplus maculatus form loose groups in wild .
A minimum group of 6-8 is recommended, in smaller groups the weaker specimens will be picked upon.
A dominancy hierarchy will be established by the time they reach maturity.
Other tank mates can be cyprinids like Danio, Devario, Rasbora spp. can be used.
They are not aggressive cichlid so should not be kept with other fish or cichlids which are aggressive in nature.

Breeding:

There are no obvious external sex differences in fin length or intensity of colour pattern. Etroplus maculatus is a bi parental substrate spawner, however they are not monogamous, i.e a permanent pairing does not take place. Weak temporary bonds are formed during mating and brood care. Observations is wild have seen them breeding in two seasons, dry monsoon period ( December to april) and monsoonal ( June to September).

A breeding site is selected and surrounding area is defended against intruders. Eggs are normally deposited in a sheltered position on the side or top of rock and are attached by short filaments. The eggs are defended by both parents.

Eggs hatch after 2 days at temperature of about 26 C. Fry are moved to pre excavated nursery pits by parents untill their egg yolks are absorbed.
Fry are free swimming in further 2-3 days, they may also remain with their parents and feed on mucus on the body of parents. This parental care can be extended till fry are big enough to defend themselves.

Eggs can also be removed after they are deposited, as the parents or other fish can eat them. if this is done the rock with eggs should be removed, water from parents tank should be used. Water flow across eggs can be simulated by using a air line close to rock. Once fry are free swimming they can be fed armetia.