User:Erc045/sandbox

Article Evaluation
Article Evaluation of Purr It seems like everything in the article is relevant to the topic but some of the information is not backed up by relevant sources. For example, I do not know if the statement that gorillas purr is true since the does not say that gorillas purr in the reference attached to this statement. It says, gorillas make a "rumbling belching" sound while eating or resting. Belching is defined as, "gas being emitted from the stomach through the mouth ," which is different then purring. An additional source for evidentiary support of this statement would make this less confusing. One claim that seems to be biased is that purring can heal or regenerate cats bones and body. Moreover that purring acts as a pain killer. There does not seem to be evidence to support this in the article. Reference 12 does not state that purring releases a hormone which acts as a painkiller. There may be evidence to support this claim, but it is not in that reference. There are multiple views on whether cats can purr and roar or not but they are not documented well in this article. I found the mechanism section very confusing because the statement, "no cats can purr and roar," leads the reader to believe that this is a true statement. The article goes on to say that this was a hypothesis. I feel that this section is contradicting and confusing. Other studies not cited in this article have suggested that, that statement cannot be confirmed. There does not seem to be any information out of date, but there was some links that did not work but have since been removed. I've looked at the talk page and much of the article has been removed because of lack of references and information that can not be verified. This article is a part of a Wikiproject called Wikiproject Cats. It has been rated as high importance on the importance scale but rated start-class on the quality scale.

Although the article is not perfect, I enjoyed reading it. It was a fun and interesting article. It just needs more evidence to support the claims being made.

Creating an Article
Lepidophagy.

Physiology
Many species of cichlid fish have evolved structural changes to their teeth and mouth, which makes them better able to feed on the scales of other fish. Other species of fish have morphology that is better adapted to scale-eating behaviour. Many of their oral structures closely resemble each other even throughout different environments but many also have specialized modifications in their jaw structure. One specific species of fish, called Roeboides prognathous, has an extremely specialized jaw structure for supporting their lepidophagous behaviour. Certain species of lepidophagous catfish, Pachypterus khavalchor, have digestive enzymes which help them more readily break down the fins, eyes, scales of other fish. There are other morphological structures that are important in scale eating habit. There are six lepidophagous cichlid species who employ aggressive mimicry strategies on their prey. The colors of the cichlid fish immensely resemble their prey but these cichlid species do not only eat the scales of the fish it resembles, but they prey on a wide range of species.

Behaviour
There are many different behaviours associated with lepidophagy. Aggression and attack behaviours like chasing and striking prey are common among Pachypterus khavalchor catfish who then eat the fallen scales of their prey. Attack behaviours for the wimple piranha Catoprion mento who's diet consists of mainly scales, is explained as a high speed attack. They ram into their prey with their mouth open biting the prey to obtain their scales. This is a very different behaviour than many species of scale eating fish who just knock the scales loose by striking the prey. Perissodus microlepis cichlid fish tears off the scales of their prey as they swim past. There are differences and similarities in lepidophagous behaviours among different species and within similar species or conspecifics. For example, The siluroid catfish attacking behaviour is similar to the Probolodus heterostomus since they both attack their prey from behind and they also follow their prey. This is dissimilar to Roeboides prognatus and Exodon paradoxus who remove scales more easily by attacking a specific area called the caudal area. Moreover, there has been many studies done on the hunting behaviours of scale-eating fish and how those behaviours have evolved over time. Certain types of cichlid species aggressively mimic the behaviours of their prey. This is a behaviour that is rarely seen in other scale eating fish.

Niche and Lepidophagy
The differences in the niche of different species may play a role in their different lepidophagy behaviours. There seems to be differences in lepidophagous behaviours and morphology within similar species in different niches. The role of adaptive radiation has been mentioned in many articles as having a role in the evolution of lepidophagy. There is some evidence to support this but much is also unclear. Some species of fish support the idea that extreme environments could be potential causes of scale eating behaviour. Some of those species are named below.

Cyprinodon Pupfish
In the case of Cyprinodon pupfish, almost all have a diet of algae and detritus but two closely related species of Cyprinodon, living in the lake Chichancanab, Mexico and in the lakes of San Salvador Island, Bahamas, are different. These two species, C. maya and another species of Cyprindon contain large amounts of scales in their diets. It is believed that this is due to adaptive radiation and the evolution of new ecological niches.

Cichlids
There is a diverse range of cichilds in lake Tanganyika in East Africa but the Tanganyikan cichlid tribe Perissodini exhibits much of the scale-eating behaviour, even though other species of cichilds in the lake do not. The species that exhibit scale eating behaviours live in deep water and have had to rapidly evolve to keep up with a changing environment and lack of food.

Trade-Offs
There are both pros and cons to scale eating behaviours. Scale eating behaviour usually evolve because of lack of food in extreme environment conditions. The eating of scales and the skin surrounding the scales provides protein rich nutrients that may not be available anywhere else. The attack behaviours and strikes that are employed to remove and eat scales have a cost of energy and possible harm to the predator. Because of this scale eating fish are quite small. Much of the time they are much smaller than their prey. Though scales are nutritious, the average amount of scales dislodged and eaten may not be sufficient to make up for the energy lost during the attack. There are other benefits of scale eating behaviours. Scales are plentiful, they grow back, and they are an abundant source of food during all seasons Scale eating behaviour usually evolves because of lack of food in extreme environmental conditions. The eating of scales and the skin surrounding the scales provides protein rich nutrients that may not be available elsewhere in the niche.