What are you feeding vieja's

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Jaws - that mix of food will be fine for your fish.




Duane, the same thing takes place in nature with apparently no ill effect.

http://limnology.wisc.edu/personnel..._Functional-Ecology-LT-cichlid-gut-length.pdf

Summary

1. Among vertebrates, herbivores have longer digestive tracts than animals at higher trophic levels, a pattern thought to reflect a trade-off between digestive efficiency and tissue maintenance costs. However, phylogenetic influences on this pattern have rarely been considered. Taxa that have undergone diversification accompanied by dietary shifts provide a powerful opportunity to examine the relationship between diet and intestine length while accounting for phylogeny.

2. In this paper we assess the relationship between diet and intestine length in the cichlid fishes of Lake Tanganyika, which are renowned for their diversity of species and trophic strategies.

3. First, we test the effect of trophic position on intestine length across 32 species, while controlling for phylogeny. Trophic position was inferred from nitrogen stable isotopes, which provide a temporally integrated, quantitative perspective on the complex diets of tropical fish. Second, we examine patterns of intraspecific variation in intestine length of an algivorous cichlid (Tropheus brichardi) along a natural spatial gradient in algal nitrogen content.

4. Trophic position explains 51% of size-standardized variation in intestine length after accounting for phylogeny. Accounting for phylogeny does not substantially alter the relationship between trophic position and intestine length, despite the existence of phylogenetic signal in both traits. Thus, diet is a strong predictor of variation at the interspecific level.

5. There is a striking inverse relationship between intestine length and algal nutrient content among populations of T. brichardi, suggesting substantial plasticity in response to food quality, and thus a strong dietary influence on patterns of intraspecific variation.

6. Diet is a strong predictor of intestine length at both intra- and interspecific scales, indicating that fish adjust their phenotype to balance nutritional needs against energetic costs. Furthermore, functional explanations for trophic diversification of cichlid fishes in the African Great Lakes have long focused on jaw structures, but our results indicate that intestinal plasticity in response to diet quality may also be an important mechanism for accommodating trophic shifts during evolutionary radiations.





Thus, we believe that the observed variation in T. brichardi intestine length is a largely plastic response to differences in the nutrient content of their algal diet. Both our broad phylogenetic survey and our intraspecific comparisons suggest that the intestine length of Tanganyikan cichlids is determined in large part by diet quality.



Ecological stoichiometry theory provides a framework for evaluating diet quality based on the degree of imbalance between the demand for a nutrient by a consumer and the nutrient content of its food resources (Sterner et al. 2002). Tropheus brichardi consumes algae that is very low in nitrogen (C : N > 18; Fig. 3) compared with its own body (C : N < 6, n = 4, P. McIntyre, unpublished data). In the light of this imbalance,the inverse relationship between algivore intestine length and algal nitrogen content suggests that longer intestines aid in extracting nutrients from low-quality foods. The overall inverse relationship between trophic position in the food web and gut length among 32 species of Tanganyikan cichlids (Fig. 2) also matches broad predictions from ecological stoichiometry.

The nutrient imbalance between fishes and their food resources increases from piscivores (no imbalance) to invertivores (moderate imbalance) to algivores (extreme imbalance), and we found that cichlid intestine lengths increase in the same order. The inverse relationship between intestine length and diet quality matches expectations from the general trade-off between maximizing the extraction of nutrients and energy from the diet and minimizing the maintenance costs of digestive tissues.



Which basically is just saying that a fish with a long gut is capable of extracting more nutrients from low quality food, vs a fish with a short gut. That doesn't mean that by providing that same fish with a more nutrient rich food it is causing stress on the fish, which in the case of the fish in this study it certainly was not. Throughout the dry to rainy seasons it become a case of feast or famine for most species of fish, and they either adapt to the change in diet, or they cease to exist.

Digestive tissues are notoriously plastic in their responses to dietary change (Starck 1999). Plasticity in gut morphology has been observed in response to fasting, increases in food intake and changes in diet (e.g. Starck 1999; Naya, Karasov & Bozinovic 2007; Olsson et al. 2007)


In the wild, the various species of cichlids have evolved & adapted to living in certain niches, which over time has forced them to become specialized feeders. Their long digestive tracts are designed as such so that in nature they can break down the complex plant matter that they consume, which doesn't mean that they can't properly assimilate more easily digestible forms of protein.

The vast majority of fish are opportunistic feeders, and most are omnivorous to a certain extent. Cichlids classified as carnivores don't just eat meat, any more than a herbivorous cichlid just consumes vegetable matter. While I believe, and my experience has been, that fiber is for the most part a non issue, that certainly doesn't mean that one should be feeding a diet high in just meat to herbivorous fish. It's all about balance, and a high quality pellet or flake will contain a good balance of amino & fatty acids from aquatic animals such as krill, fish, shrimp, etc, accompanied with the nutrients from aquatic plant matter such as kelp, spirulina, and various micro algae. BTW - commercial kelp meal is very high in iodine, so much so that warnings are often placed on bags of feed destined for horses due to the potential of iodine toxicity. Again, it's all about balance in a closed system such as an aquarium.
 
BTW - your fish always look great, Duane! This isn't a case of a right or wrong way to feed these fish, I just don't want to see people stuffing their fish with low nutrient food such as they would consume in the wild, and sparing the higher quality nutrients that they need to thrive in captivity. Obviously you don't, but some of the more inexperienced members might if they felt that feeding lots of greens from their fridge was the ideal diet for their fish.
 
My argentea and synspillum are fed omega one shrimp pellets, Hikari Cichlid Gold, fresh market shrimp, frozen bloodworms, emerald entree and algae wafers. The pellets make up the staple of their diet with the others fed a couple times per week.
 
I put mine in my natural tank that has alot of plants and gets alot of sun. He's not really interested in eating what I give him except to compete with his pals- daphnia is the exception for almost any fish though
My baby syn chews on Hikari omega one floaters and herbivore sinkers. Sometimes he'll eat bloodworms and mysis. Mostly he grazes a lot. He does like zucchini as well now that I remember I have seen him next to the otto's on that
 
No problem, I see discussion as a very positive thing, and many times my responses/opinions are added to create a situation of where questions are raised.
Many fish, Vieja included will go thru different feeding phases as they age.
Most start out when young as carnivorous, eating small crustaceans along with algae, and switch to plants as adults.
And I also agree, cichlids are very plastic in there ability to adjust to environmental changes that vary with natural changes in food supplies.
Take Herichthys minckleyi from Cuatro Cienegas.
There are 3 trophic morphs that will hatch out of any 1 spawn, a mollusc eater, a fish eater, and a detritus feeder, each with a distinctive jaw formation.
If there is a plethora of snails, that morph, will dominate until the snails have been decimated, the piscivore may then temporarily dominate, while many snail eaters die (or not), and then, when fish become scarce, the detritivore flourishes.
I tend to think all cichlids have more or less, the ability to do the same.
Whether our aquarium fish has a certain bent toward one food, and can adjust in a single generation or another is basically a guessing game, and we may only may get an inkling of the inability to do so when some unknown digestive blockage appears, or when HITH infects without an apparent cause.
Any well produced, and nutritious pellet should work.
A more prevalent problem came up while I having an interesting discussion with the curator of fishes from our local zoo this weekend.
Though small, cute, red tail catfish are very popular, and sold regularly in even the small LFSs here, they very seldom are donated to the zoo.
He believes few make it to size, because they end up dead from being fed non-nutritious, pest, and disease ridden feeder fish.
BTW - your fish always look great, Duane! This isn't a case of a right or wrong way to feed these fish, I just don't want to see people stuffing their fish with low nutrient food such as they would consume in the wild, and sparing the higher quality nutrients that they need to thrive in captivity. Obviously you don't, but some of the more inexperienced members might if they felt that feeding lots of greens from their fridge was the ideal diet for their fish.
 
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Wow thanks guys this was very informative.

Rd I think you are correct about the comment regarding inexperienced keepers feeding their fish low nutrient foods because they are herbivores. I admit that I am one of them as I was going to feed mostly veggie based foods either ways thanks guys I will just mix it up a little more

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