Food preference of the trichopteran larva Anabolia nervosa from two streams with different food availability

Abstract:

The food preference of the trichopteran shredder Anabolia nervosa from two streams with different food availability was studied in laboratory preference experiments. One stream was unshaded and had abundant growth of the submerged macrophyte Potamogeton perfoliatus. The other was shaded by trees (Alnus glutinosa) and had very sparse growth of submerged macrophytes. To test the food preference of Anabolia nervosa for terrestrial leaf litter and submerged plants we offered leaves of: conditioned Alnus glutinosa, fresh green Alnus, conditioned Fagus sylvatica, fresh green Fagus, and fresh submerged Potamogeton perfoliatus. For both larval populations conditioned Alnus was the most consumed food item, followed by Potamogeton. Larvae from the Alnus-shaded stream preferred conditioned Alnus over all other food items, while larvae from the macrophyte stream did not clearly discriminate between conditioned Alnus and Potamogeton. The three remaining food items were largely rejected. Food items were analyzed for dry matter, organic matter, fibre, nitrogen, phosphorus and toughness. Preference was not correlated to any of these food characteristics, but we suggest that they may still be important and influence food choice in a complex manner. The study indicates that the preference pattern of Anabolia nervosa is not clearly related to previous feeding habituation. The ability to feed on fresh Potamogeton is, therefore, not acquired by certain populations of larvae through long exposure to this resource in the field. The high preference for fresh Potamogeton suggests that Anabolia nervosa may actively select Potamogeton as food even when alternative food sources such as terrestrial leaf litter are abundant in the field. © 1995 Kluwer Academic Publishers.

Año de publicación:

1995

Keywords:

• feeding habituation
• food preference
• Potamogeton
• terrestrial leaf litter
• shredder
• TRICHOPTERA

Fuente:

scopus