Rapid turnover of traps in Utricularia vulgaris L.

Abstract

Utricularia vulgaris growing at Wicken Fen, England, showed rapid turnover of the trapping apparatus. New groups of leaves, each bearing many traps, were produced at a rate of 1.4-2.8 groups per day from April to September, 1987. Old leaves decayed at a comparable rate, so that individual leaves survived for less than 50 days. In July, trapping efficiency of individual bladders was greatest between 1 and 6 days of age and then declined rapidly. Very few traps more than 19 days old could capture prey and most were lost from the leaves within 32 days. The lifespan of traps was closely related to their size and position on the leaves. Because of the rapidity of changes in trap condition with age, trap age is a vital consideration in any studies of the functional ecology of U. vulgaris.

Field growth characteristics of two aquatic carnivorous plants,Aldrovanda vesiculosa andUtricularia australis

“…Shoot growth (extension) rates recorded in the present paper (Fig. 2) are comparable with other published values for Aldrovanda or Utricularia vulgaris (FRIDAY 1989, 1992, KOMIYA & SHIBATA 1998, ADAMEC 2000. The considerable variation in biomass doubling times between enclosures (Aldrovanda 8.4-21.5 days, Utricularia 9.1-33.2 days; Table 3) could still be partly due to differences between initial plant biomasses.…”

“…The number of adult leaf whorls on the main shoot was chosen as a principal measure of plant size and growth in both species, as shoot length itself is a very variable parameter that inadequately represents growth and fitness (FRIDAY 1989, KOMIYA & SHIBATA 1998, 2000. To estimate growth rate in terms of the generation of new leaf whorls, the internode between the second and third adult whorls was tagged carefully by a short piece of fine thread using a pair of forceps (FRIDAY 1989, ADAMEC 2000, RICHARDS 2001. Young leaf whorls were counted as adult if they bore functional traps (i.e., if the traps were able to suck in air bubbles, or if they contained prey/detritus) and were spatially separated by a short internode from the apex.…”

Enzyme production in the traps of aquatic Utricularia species

“…As the activities of the other enzymes were usually higher in the ambient culture water than in traps (without macroscopic prey), the enzymes could have entered the trap from the ambient water. Phosphorus (P) uptake therefore seems to be a key process within Utricularia traps, as P is a (co)limiting nutrient in most waters inhabited by Utricularia species (Friday 1989;Adamec 1997;Guisande et al 2007). The importance of phosphatase activity in trap digestion was also supported by P lachno et al inside the terminal gland cells and on the surface of quadrifid glands in traps of 26 Utricularia species, including some species grown in vitro.…”

“…Utricularia supplements normal photoautotrophic nutrition by trapping and utilizing animal prey (Friday 1989). The trap of aquatic Utricularia is a hollow utricle usually 1-4 mm long, mostly two cells thick, and filled with water.…”

“…Determining the role of utricles in the nutrition of Utricularia is further complicated by the rapid ageing of traps. In U. vulgaris, for example, most utricles complete their life cycle in 30 days or less, and during this time, continuous changes in trap function occur (Friday 1989). The age of traps is therefore a vital consideration in any study of the functional ecology of Utricularia (Friday 1989;Sirová et al 2003).…”