Fig. 6 in Ephemeral Occurrence of the Echiuran Listriolobus brevirostris (Annelida: Echiura) in Osaka Bay between 1995 and 2002; a New Record for Japan, Probably Resulting from Human-mediated Introduction

Fig. 6. Annual fluctuations in minimal dissolved oxygen content (mg/L) of the bottom water layer in the most oxygen-depleted (eastern) portion of Osaka Bay. Solid line indicates data from area formerly inhabited by Listriolobus brevirostris (northeastern Osaka Bay); dashed line indicates data from area devoid of L. brevirostris (remaining eastern portion of Osaka Bay).