‘Best by’ date: Reliability of Species Identification Based on Freshness of Material


Amphipod crustaceans can be useful environmental indicators if identified correctly and baseline data are available. Changes in species composition over time can signal environmental degradation before it moves up the food web. Baseline data are often gathered from natural history specimens that have been preserved and stored for many years. Collection methods, sorting, and storage of specimens affect the integrity of natural history specimens. Aged specimens lose defining characteristics that are crucial to proper identification, especially if not carefully sorted and preserved immediately after collecting. Freshly collected specimens have clearly defined morphological characteristics and color patterns that allow for easy identification of species. Freshly collected specimens are also more malleable than those stored in ethanol for a period of time. We hypothesize that there will be fewer identification in specimens collected more recently than in those stored for long periods of time. Amphipod collection from Panama were completed in 2005 and 2021 using similar methods (ie. coral rubble elutriation and invertebrate host dissections), sorted and preserved immediately after collection. Stacked imaging shows the differences between ethanol-preserved amphipods collected in 2005 and live material collected in 2021, supporting the hypothesis that fresh material is more easily identified than material that has been stored for long periods of time. Having access to freshly collected and sorted specimens is crucial to proper identification and, therefore, to the application of amphipods as environmental indicators.


National Science Foundation Grant: Collaborative Research: ARTS: Understanding Tropical Invertebrate Diversity through Integrative Revisionary Systematics and Training (1856421), GCSU Department of Biological and Environmental Sciences

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