Only their mother can tell them apart

Hi blog.

You’ll have to excuse my lack of  blogging this month.  Work (including a three day English camp), a few nights away, more work etc. have contributed to a lack of encounters with wildlife.

I really wish I had no access to media sometimes.  Summer in Japan is bad enough if you hate baseball as much as I do, but add the Olympics to that and it becomes unbearable at times.  Should a Japanese competitor win a medal, then that becomes headline news for the next three days, with replays of the event every half hour, live coverage of the fans watching, interviews with parents, grandparents, old teammates, fourth grade teachers… you might understand why I nearly tear my hair out.

Then, just occasionally (like a gem in a sewer) an item like this will appear on my news feed.  Like the recent news of the life expectancy of Greenland sharks, this article again emphasises just how much we don’t know about the sea.

From the Japan Times.

Twins born in Toyama aquarium’s female-only shark tank stump officials

Twins born in Toyama aquarium’s female-only shark tank stump officials


 AUG 19, 2016

Officials at Uozu Aquarium in Toyama Prefecture are scratching their heads after finding twin baby banded houndsharks in a tank that only held three female adults.

The female twins, named Mana and Kana after well-known twin actresses, were found in the aquarium’s tank on May 8, the officials said. They said it might be a case of parthenogenesis, a type of asexual reproduction in which offspring develop from unfertilized eggs. Although parthenogenesis has been observed in other shark species, the case in the city of Uozu, if confirmed, would be the first ever for banded houndsharks, they said.

The aquarium noted that a baby shark appeared under similar circumstances in April 2013, but they decided not to look into it because it died immediately, the officials said.

According to Kenji Nohara, a lecturer at Tokai University who is well-versed in the shark propagation, females of some shark species have the ability to store sperm in their bodies after mating. But Nohara said such a scenario is unlikely for the sharks at the aquarium, because the last of the three adult banded houndsharks was brought to the aquarium in January 2012, and it would be difficult to assume they mated in the wild and used sperm that was stored four years ago.

Mana and Kana, which have grown to about 30 cm long, are expected to be put on display until the end of this month. The aquarium will decide whether to ask Nohara to conduct a DNA test on them.

Banded houndsharks inhabit waters south of Hokkaido. It is an ovoviviparous fish that produces eggs that develop within the maternal body. A banded houndshark usually propagates in springtime and gives birth to 10 to 20 fry at a time.

Article ends.

Now, why can’t we have more articles like this instead of Olympic coverage?

This entry was posted in Suburban wildlife and tagged , . Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s