Turbellarian taxonomic database

Abstract / Notes

This worm is a serious pest along the Florida coast and when high salinities and temps. prevail for extended
periods of time on the oyster bars, the leech causes considerable damage. A single worm laid at least 21,970
eggs which developed into ciliated, pelagic, larvae in 11 days at summer temps. The eggs are usually brooded
until they hatch. The young grow rapidly and probably become sexually mature in less than 2 months. Stylochus
does not crawl when the temp. is below 12[degree] C and dies at 0[degree] C or 42[degree] C. It can live at
low O2 tensions. When the tension is not low a leech uses 0.1 cc. of O2 per g. body weight in an hr. at 26.5
C. Stylochi can lose 55% of their body weight by desiccation and survive. When exposed in dry dishes to air
of a 72-77% humidity they lived 8 hrs. Stylochus lives in salinities as low as 6%. but does not lay eggs in
concs. below 15%. No poison was discovered, which gave promise of use as a control for "leeches." Stylochus
enters and devours living healthy oysters and is a predator, not a parasite. A list of all the animals and
plants found on the oyster bars of Apalachicola Bay is given with remarks concerning each organism. Many of
the exps. tried with Stylochus were tried on Eustylochus meridianalis, a worm associated primarily with the
barnacles in fresher, cooler water. Any attempt at control of the oyster "leech" should take cognizance of
the worm's most vulnerable points, namely lack of toleration for low salinities and temps.

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