Is tagging with visual implant elastomer a reliable technique for marking earthworms?

Abstract

-Visual implant elastomer (VIE) has recently been employed to investigate different aspects of earthworm ecology. However, a number of fundamental questions relating to the detection and positioning of the tag, its persistence and potential effects on earthworms remain unknown. Seven earthworm species belonging to three ecological groupings, with different pigmentation and burrowing behaviour, were tagged using different coloured VIE. External inspection after two days, one week and 1, 10 and 27 months were followed by preservation, dissection and internal inspection. Tags could be seen in living specimens to 27 months, and dissection revealed that in most cases they were lodged in the coelomic cavity, held in place by septa. However, over longer time periods (more than two years), the chlorogogenous tissue tended to bind to the tags and made external observation increasingly diffi cult. Migration of the VIE material towards the posterior of the earthworm and potential loss of the tag were only observed on rare occasions, and a recovery rate in excess of 98% was recorded. By introducing a reasonable amount of VIE into segments, just after the clitellum, this technique can become a valuable tool in earthworm ecology and life history studies, particularly in short-medium term laboratory and fi eld experiments.Index terms: capture-mark-recapture methods, chlorogogenous tissue, longevity, Lumbricidae, population monitoring. A etiquetagem de minhocas com implante visual de elastômero é uma técnica confi ável?Resumo -O implante visual de elastômeros (VIE) tem sido recentemente utilizado para estudar diferentes aspectos da ecologia de minhocas. Entretanto, questões fundamentais relacionadas à detecção e posicionamento da etiqueta, sua persistência e efeitos potenciais nas minhocas permanecem desconhecidos. Sete espécies de minhocas, pertencentes a três grupos ecológicos, com diferentes pigmentações e comportamentos de escavação de galerias, foram etiquetadas com VIE de diferentes cores. Procedeu-se à inspeção externa depois de dois dias, uma semana e 1, 10 e 27 meses, seguida de preservação, dissecação e inspeção interna. As etiquetas puderam ser vistas em espécimes vivos até 27 meses após a aplicação, e a dissecação revelou que, na maioria dos casos, elas estavam alojadas na cavidade celômica, seguras no lugar por um septo. Entretanto, depois de longos períodos (mais de dois anos), o tecido cloragógeno tendeu a ligar-se às etiquetas e a difi cultar a observação externa. A migração dos VIE para a parte posterior da minhoca e a potencial perda da etiqueta foram raramente observadas, e o índice de recuperação passou de 98%. Pela introdução de uma quantidade razoável de VIE nos segmentos logo após o clitelo, esta técnica pode constituir-se em um instrumento valioso em estudos da ecologia e do ciclo de vida das minhocas, particularmente em experimentos de curto e médio prazo, em laboratório e em experimentos de campo.Termos para indexação: métodos de captura e marcação, tecido cloragógeno, longevidade, Lumbricidae...

Subcutaneous injection of visible implant elastomer in sterlet (Acipenser ruthenusLinnaeus, 1758): a study on compatibility and retention

“…Originally, VIE was developed for tagging salmon and other fish species (Northwest Marine Technology Inc., ). Today it is used with a variety of animal species (scorpions: Chapin, ; Ambystoma talpoideum : Doyle & Whiteman, ; slugs: Wallin & Latty, ; turtles: Davy, Coombes, Whitear, & MacKenzie, ; crayfish: Pilotto et al., ; snakes: Hutchens, Deperno, Matthews, Pollock, & Woodward, ; lizards: Waudby & Petit, ; earthworms: Butt, Briones, & Lowe, ). Even very small individuals such as trout alevins can be tagged with this system (Jensen, Hansen, & Thomassen, ).…”

Methods for studying earthworm dispersal

“…They are visible through the skin of the animals, particularly with a UV light. The tags are well supported by earthworms (Butt et al, 2009). They can stay up to months in their body, which is much longer than the previously mentioned tags (Butt et al, 2009).…”

Basic Research Tools for Earthworm Ecology

“…Recent work [45] has shown that it is possible, through injection of Visual Implant Elastomer (VIE), available from Northwest Marine Technology [46] to visually colour tag earthworms. In addition these tags have been shown to be retained in a number of earthworm species for more than 2 years and have no detrimental effects on growth to maturity, mating, and cocoon production in one closely studied species, L. terrestris [47]. This technique 7 may well prove to be valuable in earthworm age determination but may also reveal much from studies of population dynamics, in terms of capture, mark recapture exercises.…”