Discocotyle sagittata

{{Short description|Species of flatworm}}

{{refimprove|date=August 2014}}

{{Speciesbox

| image =

| image_alt =

| image_caption =

| genus = Discocotyle

| species = sagittata

| authority = (Leuckart, 1842)

| synonyms =

• Octobothrium sagittata Leuckart, 1842

}}

Discocotyle sagittata is a species of freshwater monogenean gill ectoparasites of Salmo and Oncorhynchus. Their lifestyle is characterised by a free-living larval stage that may be inhaled by a suitable freshwater fish host, after which they may attach upon expulsion over the gill onto a single gill filament. Upon reaching maturity, parasites can remain attached by a posterior opisthaptor with its 8 associated clamps (4 in 2 rows). Adults may reach a few millimetres in length. D. sagittata feeds on the blood of the gills via an anterior mouth part. Adults are hermaphrodite, and produce 3–14 eggs per day at 13 °C, a process which is temperature dependent.{{cite journal|title= Environmental effects on transmission of Discocotyle sagittata (Monogenea): egg production and development|date=2014-05-14 |pmid=9836315 | volume=117 |journal=Parasitology |pages=499–504 | last1 = Gannicott | first1 = AM | last2 = Tinsley | first2 = RC | issue=5 | doi = 10.1017/s0031182098003205 }} Once produced, eggs drop to the riverbed surface and at 13 °C take 28 days to develop to hatching larval forms. Major parasite burden can result in damage to the host gill and anaemia from blood loss.