it's tough to be a man -- 9/29/16

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Today's encore selection -- from Sex at Dusk by Lynn Saxon. The sexually hazardous and often subservient life of males throughout the animal kingdom:

"In some of the barnacle species [Charles Darwin] studied he noted that he found a number of dwarf males inside the female. Writing to his friend, Charles Lyell, he described how the female in two of the valves of her shell:

'... had two little pockets, in each of which she kept a little husband; I do not know of any other case where a female invariably has two husbands...'

"Darwin described these males as little more than bags of spermatozoa, and he went on to discover other barnacles with as many as 14 miniature males in a single female, speculating that any one of them might fertilize the female's eggs. ...

"In deep sea angler fish species ... only the female becomes a full adult; the male larva develops to become little more than sensory organs which are needed in order to find a female. If the male does encounter a female he then bites into her body and melds with it, reducing to little more than male gonads attached to her body. There can be multiple males attached to one female in this way, kept alive by the female and providing sperm for her eggs when needed.

46 mm female Photocorynus spiniceps (anglerfish) with a 6.2 mm long male in the middle of her back

"Many marine species have reduced males like this but we are more used to thinking about mammals, and thinking of males as being bigger and stronger than females and physically battling for status and ultimately sexual access to females. Most species, though, have smaller males than females. ...

"[For] the Australian mouse-like marsupial antechinus ... the male has a single mating season of two weeks at the end of his short (11.5 months) life. When it comes to the mating season this little male stops eating and frantically seeks females for sex. His digestive system breaks down and his levels of corticosteroids (stress hormones) skyrocket and his immune system fails. By the end of two weeks he is emaciated, ulcerated, infested, and completely physiologically beat -- and [then he drops] dead. All his energy and focus has been devoted to competing with other males, mating (if successful), and even mate-guarding females with copulations lasting up to 12 hours. Females may live and breed for another year or two. ...

"To a lesser degree males of many species have evolved bodies and behaviours that lead to a shorter life expectancy than the female of the species. Some receive injury to their bodies, sometimes fatal, in their competition for mates. Those with the bright and sometimes cumbersome ornaments are at greater risk of predation. Others are sometimes eaten by the female during mating: males in many species try to avoid this fate but at least one, the redback spider, intentionally flips his body into a position above the jaws of the female in order to be eaten during mating. Redback spider males only have about a one in five chance of finding a female and if she feeds on the male at the same time as mating she will mate for longer so the male is then able to transfer more sperm and fertilize more eggs. Somewhere in their ancestry a male had a trait for this behaviour, copulated longer, and left more offspring also with this trait so its frequency spread in subsequent generations. ...

"Consider the honeybee in the nuptial flight when a successful male mates with the queen: his 'endophallus' explodes to become a copulatory plug inside her and he drops dead. Why? It is a strategy to prevent other males from mating with the queen but for that privilege he loses both his phallus and his life (Judson 2002). What's more, the queen is able to pop out the copulatory plug and to mate again anyway."