Ovario no conspicuo. Subestadio 3: las hembras presentan huevecillos de color amarillo. Esta escala de madurez coincide con lo encontrado en este trabajo. Cabrera et al. El hecho de que las hembras alcancen la madurez sexual a los 40 o 20 mm de L. Se colocaron dos hembras y un macho en un acuario de 50 X 30 X 20 cm, los resultados fueron los siguientes.
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Checklist of anadromous species of Macrobrachium with abbreviated larval development. Species with abbreviated larval development trait in general live in the inner or endorheic basins mainly in springs. In general, these species inhabit areas between and m altitude around the mountain systems of hydrological basins. Because these mountain systems have emerged on Cretaceous and Tertiary and that the origin of Macrobrachium has been estimated in Cretaceous [ 13 ], the volcanic belt seems to be working as a geographical barrier for this group.
The Macrobrachium species colonized these freshwater habitats together with Creaseria morleyi before the emergence of the Yucatan Peninsula [ 14 ]. Four habitat types are distinguished, where the freshwater prawns with abbreviated larval development have the following unifying characteristics: freshwater all time, tropical springs and streams, and important relationship with roots of riparian vegetation trees or shrubs , the values of oxygen dissolved are high, and the pH trend toward alkalinity and few sites were recorded coexisting with another Macrobrachium species complete larval development species.
In general, all sites are clean without records of pollutants, both solids and dissolved. There are federal laws to protect the wildlife where it is stated that for some species that are examined with protected labels such as vulnerable, dangerous to extinct, or only dangerous, the fisheries are forbidden. In this case, for most Macrobrachium species, this law is not applicable because there are only two species Macrobrachium villalobosi and Macrobrachium acherontium, both protected from underground environments.
So, each state establishes different regulations to grant the permissions to make a sustainable fishery. There are two main problems for the most species, the first one is the pollution that occurs in the high areas where the big cities are established because the regulations to eliminate the waste waters are null, so several elements such as heavy metals or nitrogenous or phosphorus species are released without any previous treatment.
We suggest some sewage water treatment by using in first instance some local plants and increasing the treatment factories for this. However, the most important action is to prevent the indiscriminate water use because in the cities, small or big, there are few consciences about the implications on the water use.
If we apply several strategies of environmental education, it is possible to attend the problem better. The other problem is establishing new dams in the middle of rivers to avoid the normal migrations to upstream and downstream as occur in several places. For those species that are living in the inner basins, the main problem is that they are living in specific places where they have a microdistribution and few species have several populations in different subbasins. So, any change in the environment could affect the populations that in some cases have been reported only in the locality type.
A decrease has been reported in the population size of several species that normally live upstream. However, there are several records where the species of Macrobrachium walked out from rivers and climbed just beside the dam wall and then continued their migration upstream; so, if the dams include some passage or some strategies such as fish ladders, we cannot interrupt the normal migration.
Fisheries and commercial data In the slopes of Pacific and Gulf of Mexico, important fisheries on these resources exist. In general, the local people use local nets atarrayas or traps nazas to catch different species. The bigger species from both sides are Macrobrachium carcinus and Macrobrachium americanum; these species reach a maximum body length of 30 cm and a maximum weight surpassing g.
Another species from both sides are Macrobrachium tenellum and Macrobrachium acanthurus, both have a similar size to the most popular penaeid shrimps and several times they are sold as marine shrimps. Both species are very popular in the fisheries on the coastal areas, while for the first two species, the fisheries are more common in the middle of rivers where the ponds are deeper and the last important fisheries focus on Macrobrachium heterochirus and Macrobrachium occidentale that live in the waterfalls where the oxygen dissolved in water levels are higher in comparison with those reported in the coastal areas [ 15 ].
Macrobrachium peguense -Inlesee Burma (DNZ) (Planarienfresser)
Macrobrachium faustinum - Boxerhandgarnele