Featured Research

from universities, journals, and other organizations

Sneaky squid: Why small males have big sperm

Date:
August 10, 2011
Source:
BioMed Central
Summary:
Male squid employ different reproductive strategies depending on their body size. New research shows that the divergent mating behavior of male squid has resulted in the evolution of different sperm sizes.

Male squid (Loligo bleekeri) employ different reproductive strategies depending on their body size. Research published in BioMed Central's open access journal BMC Evolutionary Biology shows that the divergent mating behavior of male squid has resulted in the evolution of different sperm sizes.

Large male squid compete for females by courting them with flashy skin color-change displays. Once a female has chosen her partner they mate in an above and below position so that the male can place his sperm inside the female's oviduct. He remains with the female until she spawns, ensuring that his sperm fertilize her eggs and that no other males have a chance to mate with her. At the moment a female lays her eggs, small 'sneaker' males rush in and mate with her, head to head. These small males place packages of sperm by the female's mouth in the hope that their sperm have a chance of fertilizing the eggs as they leave the female's body.

When researchers from London and Japan looked at the sperm produced by small sneaker males and large consort males they discovered that the sperm produced by the sneaker males was larger than that of the consorts. Dr Yoko Iwata from University of Tokyo said, "Sperm size is likely to be an adaptation to fertilization environment, either inside the female or externally, rather than competition between sperm, because the fertility and motility of sneaker and consort sperm were the same."

Overall, the larger males' strategy resulted in higher paternity rates -- but for smaller males, who cannot win a female by fair means, being sneaky gives them a chance of passing on their genes.


Story Source:

The above story is based on materials provided by BioMed Central. Note: Materials may be edited for content and length.


Journal Reference:

  1. Yoko Iwata, Paul Shaw, Eiji Fujiwara, Kogiku Shiba, Yasutaka Kakiuchi and Noritaka Hirohashi. Why small males have big sperm: dimorphic squid sperm linked to alternative mating behaviours. BMC Evolutionary Biology, 2011 [link]

Cite This Page:

BioMed Central. "Sneaky squid: Why small males have big sperm." ScienceDaily. ScienceDaily, 10 August 2011. <www.sciencedaily.com/releases/2011/08/110809212436.htm>.
BioMed Central. (2011, August 10). Sneaky squid: Why small males have big sperm. ScienceDaily. Retrieved August 30, 2014 from www.sciencedaily.com/releases/2011/08/110809212436.htm
BioMed Central. "Sneaky squid: Why small males have big sperm." ScienceDaily. www.sciencedaily.com/releases/2011/08/110809212436.htm (accessed August 30, 2014).

Share This




More Plants & Animals News

Saturday, August 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

We've Got Mites Living In Our Faces And So Do You

We've Got Mites Living In Our Faces And So Do You

Newsy (Aug. 30, 2014) A new study suggests 100 percent of adult humans (those over 18 years of age) have Demodex mites living in their faces. Video provided by Newsy
Powered by NewsLook.com
Experimental Ebola Drug ZMapp Cures Lab Monkeys Of Disease

Experimental Ebola Drug ZMapp Cures Lab Monkeys Of Disease

Newsy (Aug. 29, 2014) In a new study, a promising experimental treatment for Ebola managed to cure a group of infected macaque monkeys. Video provided by Newsy
Powered by NewsLook.com
Killer Amoeba Found in Louisiana Water System

Killer Amoeba Found in Louisiana Water System

AP (Aug. 28, 2014) State health officials say testing has confirmed the presence of a killer amoeba in a water system serving three St. John the Baptist Parish towns. (Aug. 28) Video provided by AP
Powered by NewsLook.com
Raw: Australian Sheep Gets Long Overdue Haircut

Raw: Australian Sheep Gets Long Overdue Haircut

AP (Aug. 28, 2014) Hoping to break the record for world's wooliest, Shaun the sheep came up 10 pounds shy with his fleece weighing over 50 pounds after being shorn for the first time in years. (Aug. 28) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins