There's an excellent essay by the evolutionary biologist Steven Jay Gould about sexual dimorphism [0], mostly in the context of anglerfish, but which also menti

There's an excellent essay by the evolutionary biologist Steven Jay Gould about sexual dimorphism [0], mostly in the context of anglerfish, but which also mentions a parasitic mollusk, of which the male embeds itself in the female body and looses most all organs except the testes. That same essay leaves us with this gem of a quote: "In some ultimate Freudian sense, what male could resist the fantasy of a life as a penis with a heart, deeply and permanently embedded within a caring and providing female?" [0] https://books.google.com/books?id=o6g2tvN0nJoC&lpg=PT15&ots=dAd72sWoLa&dq=gould+big+fish+little+fish&pg=PT15&hl=en#v=onepage&q&f=false https://books.google.com/books?id=o6g2tvN0nJoC&lpg=PT15&ots=...