In the lower reaches of the Amazon rainforest, terrestrial invertebrates make up the majority of the gut contents of most fish species. Fruits and seeds are the preferred food for large fish that live in medium and higher rivers. Riparian wetlands increase the area of ​​this active exchange zone and retain these energy resources longer than stream banks alone. Aquatic organisms also contribute to terrestrial food webs. For example, bats are known to forage in riparian wetlands from secondary production of emerging insects, and coastlines are home to numerous terrestrial predators such as spiders, tiger beetles, and coastal lizards. Experimental disruption of these connections showed that altering riparian habitats could reduce energy transfer between canals and riparian zones. Globally, aquatic organisms of all kinds are among the most endangered species due to pollution and habitat loss. This has drawn attention to the need to record aquatic habitat fauna and understand the habitat variables that have the greatest impact on species occurrence and distribution. Mayflies as a group are known to be sensitive to habitat disturbances and have been used worldwide to monitor changes in the quality of aquatic systems, but it is important to control species distribution and their occurrence. Our knowledge of what does is still incomplete in many regions. Intensive research has been carried out in many regions of the world to build databases from which to derive conservation strategies. This kind of work for recording the mayfly fauna in Madagascar deserves special mention. Madagascar's fauna contains some of the most spectacular species of primitive mayfly, with over 90 new species described since 1990. Survey work in Madagascar and other parts of the world continues to make intriguing discoveries of new species and new distributions, even in previously well-sampled areas. Many aquatic species compete with each other through hostile interactions. For example, many species, including many fish and insects, actively exclude other individuals (both conspecifics and other species) from their territory. In streams, some benthic insects defend their foraging areas by trapping airborne particles. Their density can be very high, simultaneously leading to competition for exploitation and interference. Indeed, many benthic organisms may simultaneously compete for space and exploitation through interference competition for food. For example, zebra and quagga clams may grow densely in the shells of large clam species, resulting in reduced growth or mortality of large clam species from both invasion and exploitative competition. In many aquatic species, females lay eggs before fertilization. The male then places his seeds in the water. By the time gametes are formed, both mother and father may have left. Some species of fish simply scatter their eggs in running water. Other species lay eggs on the surface. This latter action opens the door to rudimentary parental care. Females are able to protect the eggs and young hatchlings (the very small fish are called juveniles). Other species of fish, such as bettas, build bubble nests where spawning takes place. Some fish are kept in the mouth to protect the fry. Salmon live in the open ocean, but spawn and die in freshwater streams and rivers where the next generation hatches.