Others relate mesozoa to a group including annelids, planarians, and nemerteans. Other coastal nemerteans have devastated clam beds. The Lophotrochozoa includes the molluscs, annelids, brachiopods, nemerteans, bryozoa and entoprocts. This toxin is also present in many other species ranging from toads to nemerteans. Very little is known about the ecology of pelagic nemerteans, including diet and feeding behavior. Free-living marine suctorial nemerteans appear to be food specialists feeding primarily on amphipods. Like other nemerteans, "Lineus longissimus" feeds using its eversible proboscis. Traditional taxonomy says that nemerteans are closely related to flatworms. Most nemerteans are solitary, free-living animals. Enoplan nemerteans are known from all continents and all seas. Some groups of Nemerteans also produce larvae that are very similar to the planula. Most nemerteans are carnivores, feeding on annelids, clams and crustaceans. Most nemerteans have two to six ocelli, although some have hundreds. Also, many nemerteans produce toxins of which some are nicotinic agonists. Most nemerteans are dioecious, although there are a few hermaphroditic hoplonemerteans.