2007 Calvino Gas filling of the swimming bladder of south American annual fish larvae Abstract The South American annual fish of the Rivulidae family bury their eggs in the substrate (generally with predominance of the slime). The eggs remain in a diapause state during the dry season until the hatching takes place with the first rains of the "wet season". When the larvae hatch, they carry out retrograde movements through the substrate until they reach the surface of it. At the time of the hatch, the gas bladder is empty and in the next 24 hs takes place the filling of it, mainly with oxygen and carbon dioxide from blood. The appearance of "belly sliders" is a phenomenon that occurs frequently in annual Killifish (Cyprinodontiformes) of the Rivulidae family of South America. This denomination comes from the fishkeeping hobby and refers to the post-larvae that after the hatching do not manage to establish a normal swimming by problems in the gas filling of the bladder gas. In the present work the influence of the substrate and the maximum standard length (SL) of different species in the "belly sliders" appearance was studied. For this an experiment was made (n-5) in which the percentage of "belly sliders" of a set of post-larvae that hatched buried in the slime (condition A) was compared with the percentage of "belly sliders" of a set of post-larvae hatched without the slime (condition B). Another experiment was made as well in which the percentage difference of belly sliders between conditions B and A, for different species, was compared against the maximum standard length (SL). It was concluded that the appearance of "belly sliders" in the condition A is minor than B and that it does exist a tendency to the increase of post-larvae with a defective filling of the bladder gas (belly sliders) with the increase of the maximum SL that the species can reach. A hypothesis of how this could happen at a physiological level and another one about the evolutionary origin of this characteristic are given. A series of other related experiments are shown and discussed. Based on these hypothesis it is considered that the exercise that the post-larvae do to get out of the substrate after the hatching and the availability of oxygen are factors that could affect the adequate filling of the bladder gas. 2009 Sanabria Effects of commonly used disinfectants and temperature on swim bladder non-inflation in freshwater angelfish, Pterophyllum scalare Several types of commonly used fish egg disinfectants increase the risk of swim bladder disorder in fish, a new study reveals. In an effort to prevent fungal growth, many fish breeders use various chemicals, such as methylene blue, hydrogen peroxide, acriflavine and chloramine-T to aquariums where eggs are kept. This practise is especially common among breeders who will not let the parents stay with eggs and fry. Many fish species carry out parental care and eggs from such species often depend on one or both parents gently fanning fresh water over them and manually removing any unfertilized eggs from the batch. Without such parental care, the eggs easily succumb to fungi unless the fish breeder adds some type of fungicide to the water. The new study, which focused on Angelfish (Pterophyllum scalare), revealed that some of these chemicals may be responsible for a swim bladder disorder in developing fish. In fish suffering from this type of disorder, the swim bladder can not inflate properly and the fry fails to develop into a fully free-swimming adult. Among aquarists, such fish are commonly known as “belly sliders” due to their peculiar way of moving around the fish tank. Methylene blue Eggs hatched in the presence of 1, 2 and 5 ppm methylene blue exhibited significant increases in swim bladder non-inflation (11%, 9% and 33%, respectively; none in controls). Time of exposure to methylene blue was a key factor. Exposure for up to 1 day post-hatch did not affect swim bladder non-inflation, but exposure from 2 days onwards significantly increased swim bladder non-inflation. Hydrogen peroxide Hydrogen peroxide at 250 ppm significantly increased swim bladder non-inflation (65% comparing to 27% in the control). Higher concentrations resulted in 100% mortality. Acriflavin Exposure to acriflavin at 2.25 ppm, but not 1.25 ppm, significantly increased swim bladder non-inflation (75% and 52% respectively; 20% in controls). Chloramin-T Chloramine-T did not significantly affect swim bladder non-inflation.

2020 pfk 'Belly sliders' caused by egg disinfectants, says study A new study on the effects of fish egg disinfectants on angelfish has shown that the chemicals can greatly increase the chances of fry developing swimbladder disorders - incorrect temperatures have similar affects. Fish breeders regularly add disinfectants, including methylene blue, acriflavine, hydrogen peroxide and chloramine-t to batches of eggs - particularly those of egg-depositing species, such as cichlids - in an attempt to prevent the broods becoming infected by pathogenic fungi. However, scientists now believe that the chemicals are responsible for a disorder in the developing fish that prevents their swimbladder inflating correctly. Incorrect temperatures are also believed to trigger the disorder. The non-inflation of the swimbladder in fry results in fish that fishkeepers refer to as 'belly sliders' as they fail to become fully free-swimming.