Therefore at higher population densities, when mating opportunities are not rare, the gonochoric individuals will have a higher fitness because they have more energy.Monogamy is also analogous to rare encounters but true monogamy is rare (1 partner for life).Dan Corbin, founder of Wisconsin Red Worms, shows off a glob of red worms as they are prepared for shipping from the basement of his Richland Center home.Corbin has been growing the worms for over 10 years but now raises them on a farm northeast of the city.In these groups, hermaphroditism is a normal condition, enabling a form of sexual reproduction in which either partner can act as the "female" or "male".For example, the great majority of tunicates, pulmonate snails, opisthobranch snails and slugs are hermaphrodites.So it seems logical that the hermaphrodite way of reproduction is more successful than the "normal" way. The group of fish known as hamlets en.wikipedia.org/wiki/Hamlet_(fish) are simultaneous haermaphrodites, like snails.
Very few of the worms are skewered with a fishing hook and gobbled up by a blue gill, perch or the resident brook trout.The anatomical description of the whole animal has been completed at the electron microscopy level and its complete cell lineage, which is invariant between animals, has been established (Brenner, 1973; Byerly et al., 1976; Sulston et al., 1983; Wood, 1988a; Lewis and Fleming, 1995). Various tissues open to the outside through this cuticle (Intro FIG 3). There are two sexes: a self-fertilizing hermaphrodite (XX) and a male (XO). The excretory pore is located at midline on the ventral side of the head (Intro FIG 3E). sort of like asking 'why do we bother getting married and buying houses when we could just hook up at a bar every weekend?' hermaphrodites can reproduce more easily, but other organisms invest more in their offspring and also often have a harder time getting around to mating. It is perhaps easiest to address the question by countering it and asking why dioecy (2 sex systems/2 gonochoric types e.g. As you have pointed out there are obvious advantages to being a hermaphroditic species such as more chance of mating - more likely to provide an advantage at very low population densities where interactions are infrequent.no judgments here, just trying to make it pretty plain. There are two key disadvantages of hermaphroditism which I will briefly cover but have been discussed in this paper and probably other costs. Maintaining the capacity to produce male and female gametes will be more costly than maintaining one.