Freshwater shrimps can do a little bit. They do not stress bioload much and too fast for an axolotl to eat.They won't make your tank into sparkleing clean waters and glass devoid of life, but they can help. Other types of shrimp are better at eating axolotl leftover food than eating algae. If you chose a shrimp, do your homework first, especially if you want your shrimp to reproduce themselves.
Oh, there are also plants that are good algae busters. One is Hornwort(Ceratophyllum demersum). It grows very very fast competing with algae. Eventually it can take over and prevent any noticable algae from appearing. It can make a nice background wall if one puts rocks to hold a few stems down. Hornwort needs lots of light to grow even faster.One does not neceasarilly need to get critters to make algae go away.
(Message edited by mantighoul on February 05, 2007)