Macroinvertebrate nutrient excretion incubation

Knowledge graph centered on Macroinvertebrate nutrient excretion incubation with 71 nodes and 173 connections. Top connected: Rocky Mountain Biological Laboratory, Gothic, Colorado East River Valley, Diptera, Mayflies.

Method synopsis

Organisms are incubated in filtered pond water for one hour to measure nitrogen and phosphorus excretion rates through water chemistry analysis before and after incubation.

Synthesized from method descriptions across 5 papers using this protocol.

Procedure from a recent peer-reviewed implementation

Steps below were extracted from the most recent peer-reviewed implementation of this protocol in the corpus — Animal-Driven Nutrient Supply Declines Relative to Ecosystem Nutrient Demand Along a Pond Hydroperiod Gradient (2021), Ecosystems. The protocol was originally introduced by Influence of handling stress and fasting on estimates of ammonium excretion by tadpoles and fish: recommendations for designing excretion experiments (2009), Limnology and Oceanography Methods. Implementations in other papers (listed below) may differ.

1. Invertebrate excretion measurements
   Collected animals and held for 0.5 to 1.5 hours in plastic bags to measure ambient excretion rates while minimizing stress or starvation effects. Placed bagged animals in shaded areas of each pond to maintain ambient temperature. Varied number of individuals (1-10) and volume of filtered pond water (100-200 mL) adjusted per taxon size. Collected 3-15 replicate excretion measurements for each taxon (223 total replicates across all taxa). Included 2-4 controls without animals to measure changes in ambient nutrient concentrations (52 total controls).
   Quantities: 223 total replicate excretion measurements, 3-15 replicates per taxon, 1-10 individuals per measurement, 100-200 mL filtered pond water volume, 52 control measurementsDuration: 0.5-1.5 hour incubations, measurements collected throughout summerConditions: Ambient temperature maintained, shaded areas of ponds, <4°C temperature variation among replicates
   Equipment: plastic bags, filtered pond water
2. Salamander excretion measurements
   Processed salamanders in nearby shaded tent to minimize handling, thermal and oxygen stress. Placed individual salamanders in 1 L of filtered pond water. Estimated individual salamander dry mass using wet mass and conversion factor of 0.233. Measured differences in ammonium-nitrogen (NH₄⁺-N) and soluble reactive phosphorus (SRP) in filtered water collected before and after incubation (0.5-1.5 h).
   Quantities: 35 replicate measurements, 1 L filtered pond water per individual, 0.233 wet mass to dry mass conversion factor

Typical Equipment

• bags
• water filters
• filtered syringe
• glass tubes
• amber Nalgene bottles
• ice
• Thermo Scientific GENESYS 10S UV-VIS Spectrophotometer
• Turner Designs Trilogy Fluorometer

Output Measurements

• mass-specific nitrogen excretion rate
• mass-specific phosphorus excretion rate
• N:P excretion ratio

Papers Using This Protocol (5)

Species Studied With This Protocol

Places Where Used