Publication2 med aquascape Publication1cs complete | Page 68

height and width of 60cm. I wouldn’t recommend adding conspecifics; perhaps only in very large aquaria, but small to medium sized centrals like exCichlasoma salvini or groups of Thorichthys sp. should do well. Feeding is very straight forward. They will accept all sorts of dry foods like flake, floating pellets and food sticks. Chopped up mussels and prawns are eagerly excepted, full of proteins which will help bulk up your fish. Stay clear from mammalian foods like beef heart. I personally don’t see the need in offering these types of foods as the alter- natives mentioned earlier will benefit your fish in the long term. Other important foods to offer are vegetables. Paratheraps sp. is known to be herbivorous detri- tus feeders and makes up a lot of their diet in the wild. Offer thinly sliced cucumber or quickly blanched lettuce and spinach. Blanching helps soften the vegetable, so will be easily digested. For convenience, offer them with a lettuce clip. The fish can then graze at their own leisure. The tank can be decorated with rocks and wood. Plants are rarely encountered, so will probably be up rooted and eaten. A sandy substrate is pre- ferred rather than a pea gravel one, as fish find it easier to sift through. Sand also looks better and natural to the fish. You can either use children’s play pit sand or pool filter sand. Pool filter sand is starting to take preference with many hobbyists as it is heavier and doesn’t compact as much as play pit sand. Periodically stirring the sand with a tool will ensure the sand stays fresh. The tank used is 8ft, 2ft, 4ft wide and fitted with a ‘Back to Nature’ background. I decorated as natu- ral to their home environment as best I could. This included large boulders and beech tree wood, ar- ranged as if there is overhanging roots penetrating through the water surface. Paratheraps sp. ‘coatzacoalcos live in faster flowing bodies of wa- ter, so we can try to replicate this by adding a power head or positioning a spray bar so that it agitates the water surface. Bright clean water is good, so regular water changes will benefit and aid growth and vitality. Water quality needs to be taken in account, so as a guideline we should be looking at medium to hard alkaline water with a pH of 7 to 8 and a temperature of 72 to 82. This range seems the best compromise when accommodating water conditions to centrals. The higher temperature range will produce lively fish and prolific spawning activity, so adjust to lower levels if required. Sexing and spawning. For the benefit of the article the fish described are a population from the Rio Grande. Other populations may have different traits when de- scribing sexing differences. Early sexual dimorphism in sp. coatzacoalcos can be weak. Rio Grande females will display a dark- ened area on the dorsal fin, this is usually seen when females are dominant or becoming sexual- ly mature, females can also display subtle pink coloration around the operculum. Males tend to display black dappling on the unpaired fins and also develop a larger head profile and thicker body than the female. As the fish become larger and sexual mature the differences are quite ap- parent. Males develop a lovely blue colour with a yellow green iridescence on the base of the dorsal. Red is displayed on the edges of the dor- sal and caudal fin. The thickness of the red band on the caudal can vary between populations. Females can develop an overall golden/brown colour, but not so much the strong blue colour of the male fish. I found that they can be early developers and it's not unusual for fish to start pairing up at only 4". Two fish will separate from the group and start body shimmering and cir- cling each other. It's interesting to note that their eyes change to a bright orange/yellow col- our and the dark lateral band will be broken up somewhat. The female’s dark blotch will certain- ly become noticeable at this stage. Bonding can be quite rough with occasional jaw locking and 32