Growth, survival, and tag retention results from PIT tagging Santa Ana Sucker in a mesocosm experiment

The Santa Ana Sucker (Pantosteus santaanae) is a federally threatened species of ray-finned fishes endemic to the Santa Ana, San Gabriel, and Los Angeles Rivers in southern California. Seasonal limitations on conventional sampling and inconsistencies in survey methodologies have led to an incomplete understanding of Santa Ana Sucker population dynamics. Therefore, alternative sampling methods that are not limited by these constraints are needed to help fill important knowledge gaps in Santa Ana Sucker biology and life history. One option is to implement passive integrated transponder (PIT) tagging technology to identify and track individuals. This study tests the effect of PIT tag size (8- or 12-millimeter) on mortality, tag loss, and growth of Santa Ana Sucker over a short (30 day) time period.