Spiders. Part 4. Spider courtship.
RECALL, from Part 2. That a male spider risks his life going a-courting.
A large, hungry female, just waiting for a nice meal.
A male Spider’s approach and courtship of a larger female can be extremely dangerous as she is always very hungry A stab by her fangs can paralyze him, enabling her to suck out his dissolved flesh at her leisure. To mate with her he must persuade the female that he is not her next meal but a healthy male come-a-courting.
The various species have different approaches, often it takes the form of a flamboyance dance. Googly the “Peacock Spider” to observe this performance.
Once she is sufficiently memorized by his performance he will climb over her back and reach around with his palps and insert his seed into a special chamber called a spermatheca, where it can be stored until she is ready to lay her eggs.
Another species will present his female with a gift of food wrapped in silk, and while she is busy eating, he will then have his way with her.
Yet, another method is that of the male trying to hold on to the females’ fangs preventing her from ingecting venom into his body while attempting to mate.
A better approach is to tie the female down, as in the case of a Crab spider, yet she is quite capable of breaking free of her bounds once he has finished.
Perhaps, the best method a male can take is to be exceedingly small, too small to eat. As in this case, the Black Widow and the giant Nephila spider are two examples, where the male simply walks all over the female without hindrance and mating is an easy affair.
How about developing two holes in the head to aid with the safe mating process. Some members of the money spiders (Linyphiidae) have developed two pits in the head region to harmlessly house the females’ fangs while mating. At the same time, these pits house hairs and glands that secrete an aphrodisiac. Other species of linyphiids have protrusions and nobs on the head, acting as a safe anchorage place for the female’s fangs. In addition, these nobs, like the pits mentioned above are accompanied by a group of hairs that produce a pheromone that we believe will calm her down while the male mates with her.
Yet another strategy is to allow yourself to be eaten as you mate with your female of choice. Certain species of Orb-web spiders reproduce in this way. The female spins a horizontal mating line of silk enhanced with a hormone to attract a male. As she feels the approach of a male, she will drop down a short distance on a line of silk. The male will also drop down in an equivalent way close to her. She will impale him with her fangs and paralyze him, yet this will not prevent his performance plus he is now in the perfect position to mate with her. As an added bonus his body will enrich the eggs and enhance his genes for the next generation.
Another, is the Mimetidae or Pirate spiders use sex to obtain their next meal. This female will enter an orb-web of a different species plucking the silk threads as she approaches imitating a courting male or a struggling prey item. Then quickly inject venom that is designed to kill the other spider rapidly. She will then proceed to suck out its body fluids leaving just an outer skin. The Ero canionis species is an example of a cannibal, and how they reproduce I do not know or cannot even guess.
Conclusion.
In spider courtship, the male spider has a lot to lose, his life! The female on the other hand has a possible meal arriving. she needs as much food as possible to provision the volk of her further eggs.
The male to survive the encounter must indicate that he is a suitor of the same species, healthy and desirable, and able to protect himself from the females’ fangs.
Read-On Part 5. Sexual Selection in Spiders.
Happy reading – JohnH.
Please visit our next Spider blog about spiderlings struggle to survive to adulthood. (coming soon).
