Sheepshead Fish: Vulnerable and Gender Fluid Yet Mighty Tasty

The skeptical cardiologist and his Eternal Fiancee’ have escaped dreary and oceanopenic St. Louis and are spending a week in allegedly sunny and definitely beachy San Diego.
Upon arrival we took in a Farmer’s Market in Little Italy and stumbled into Ironside Fish and Oyster.

Always in search of heart-healthy, unique and local fish dishes, I spotted on the menu a luncheon special of sheepshead fish.

California sheephead (Semicossyphus pulcher), turned out to be a fascinating and most delicious fish.

Before I could order it, I had to verify that I wasn’t contributing to the extinction of a species.  The IUCN Red List of Threatened species lists the CS as “vulnerable” because:

“The natural history of this species, including its limited geographic range along inshore habitat, the likely increasing interest in the fishery and the currently unsustainable fishing levels (according to the models of Alonzo et al. 2004), together with the difficulties in enforcing existing regulations strongly suggest that this species will continue to decline if stronger protective action is not put into place. “

After learning the CS was vulnerable, I had to make a critical decision: should I eat it before it disappeared, robbing me of a chance to ever taste it, or should I order something that wasn’t vulnerable, thus contributing to the preservation of the continuing biodiversity of the planet. I elected to taste it.

Gender Fluid Fish

Further research revealed that the CS transitions from a reproductively functional female at birth, to a functional male during the course of a lifespan in response to social factors (?reverse Bruce Jenner).
According to evolution.berkeley.edu this is termed sequential hermaphroditism:

In some sequentially hermaphroditic fish species, animals develop first as male and then switch to female (a condition called protandry), and in others, the individuals develop first as female and then switch to male (protogyny).

Clownfish (as in Finding Nemo) do the opposite of the sheepshead and are protandrous:

This species lives within sea anemones in groups of two large fish and many small fish. The two large fish are the only sexually mature fish and are a male and female breeding pair. All of the smaller fish are male. If the large breeding female is removed, her male mate changes sex to female and the next largest fish in the group rapidly increases in size and takes over the role as the sexually mature male.

 
Do not make the mistake of looking at this youtube video while waiting for your sheepshead entree’ as I did. The disturbing human-like teeth will not be part of your meal.

Finally, the 4 ounces of CS arrived, perfectly prepared a la plancha,
with an accompanying lemon butter sauce that was divine. Although butter is not officially a big part of the Mediterranean diet, frequent readers of the skepcard now that dairy fat does not make you fat or promote heart disease, and is fine (in moderation of course) as part of a heart-healthy diet.

Speaking of lingering bad dietary advice, if you investigate the nutritional content of sheepshead at a site like SELF Nutrition, the old canard that we should be limiting our dietary cholesterol raises its ugly head. Because sheepshead contain significant amounts of cholesterol (presumably from carnivorously munching on shellfish with its scary human-like choppers), the misguided nutritionists at SELF Nutrition and other would-be nutritionistas pronounce it as not optimally healthy.

Semiccossyphusilly Yours
-ACP
PS. If you’d really like to get your nerd on about sequential hermaphroditism check out this graphic showing the independent evolution of this feature across different phylogenetic lineages!