The ultrastructure of the posterior gut and caecum inAlona affinis (Crustacea, Cladocera)

The presence, nature, and role of gut microflora in aquatic invertebrates: A synthesis

“…Arthropods, particularly Crustacea, have received the most attention with regard to the presence of gut microflora. Bacteria have been reported in the guts of Macrura, including prawns [44,93], shrimps [61,62,63,153,188,223], crayfish and lobsters [147,190], Brachyura [56,105,189,190,206], Isopoda [112,186,225,226], Copepoda [148,187], and Cladocera [89]. Bacteria have also been reported in the guts of Amphipoda [8,142], research being focused on deep-sea amphipods [60,110,178,192,221].…”

“…In echinoderms, bacteria are reported in the foregut [191], intestine [59,130,131,201], hindgut [191], and cecum [57]. In Annelida, bacteria have been recorded in the foregut [10], midgut [10,119], hindgut [10,89,112,119], and the cecum [89]. A single species of ascidian has been reported to have bacteria in the endostyle, gut contents, feces, and inhalent siphon [180].…”

“…These studies also do not give information about whether different types of microflora occur in different regions of the gut, or of the sites of colonization within a particular region, i.e., whether bacteria are epimural, free in the lumen, or attached to specific structures. Those studies which do examine a number of different regions of the gut indicate that the hindgut is an important region of bacterial colonization in Crustacea [8,10,62,89,93,105,119,153]. Although bacteria have been reported in the foregut, midgut, and digestive gland of some crustaceans, these regions of the gut are not colonized in all species investigated [8,10,89,93,147,153].…”

“…Those studies which do examine a number of different regions of the gut indicate that the hindgut is an important region of bacterial colonization in Crustacea [8,10,62,89,93,105,119,153]. Although bacteria have been reported in the foregut, midgut, and digestive gland of some crustaceans, these regions of the gut are not colonized in all species investigated [8,10,89,93,147,153]. The presence of a rich and varied flora in the hindgut and relatively poor utilization of the foregut by microorganisms have been reported for two other arthropod groups, insects and millipedes (for review see [24]).…”

Toxicity of Vegetable Tannins on Crustacea Associated with Alpine Mosquito Breeding Sites

“…Controls and samples treated with tannic acid solutions from 0.125 to 0.500 mM for 4,6,8,12, and 24 h were "xed by following the methods of Elendt (1989) and Gunzl (1990). Fixation was for 2 h at 43C in 2.5% glutaraldehyde in 0.1 M cacodylate bu!er before rinsing overnight at 43C in the same bu!er and post"xation 2 h at 43C in 2% osmium tetroxide in the same bu!er.…”