BALEEN (WHALE WHISKERS)

Baleen is an elastic horny material made up of keratin, the same fibrous protein material found in fingernails, hair, and feathers. Baleen is used in a filter-feeding system that hangs in rows from the roof of the mouth of a baleen whale. The whale pushes a scooped-up mouthful of water, partly shuts its mouth, and then uses it tongue to push the water through the “hairy” baleen. The baleen acts as a strainer/filter to catch small animals, such as krill, which are numerous tiny arthropods that float in sea water.

Partial view (100-cm-long) of piece of baleen from an eastern Pacific whale.

Baleen whales, which currently are made up of 16 species, belong to the mysticetes, which are also called the “whalebone whales.” Some examples of baleen whales are: the bowhead, gray whale, blue whale, sperm whale, humpback whale, beluga, and fin whale. Baleen whales all have two blowholes (nostrils) on the top of their heads.

Note: the other major group of whales are the toothed whales (e.g., killer whale), and they have only one blowhole.

Some gastropods, all of which have tiny limpet-like (inverted “V” shaped shells), can live in decaying baleen. There are four known families of these gastropods: pyropletids, cocculinids, osteopeltids, and neolepetopsids. A recent paper by Marshall and Walton (2021), which is given at the end of this blog post, described an osteopeltid limpet gastropod that was found to feed on baleen off the coast of New Zealand, in waters of 377 to 1042 m depth. How this gastropod and other ones like it metabolize the tough and essentially inert baleen is unknown, but it is probably related to the action of symbiotic bacteria within the gastropod gut. The shape of this gastropod is illustrated below.

Oval outline of the shell of the deep-sea osteopenia gastropod limpet Baleenopleta rotunda, top view, 12.5 mm diameter. Top view, height 4.5 mm of same B. rotunda specimen as shown below.

Side view, height 4.5 mm of same B. rotunda specimen as shown above.

Numerous minute specimens (small ovals) of Baleenopleta rotunda in living position in the narrow spaces between the “ribs” of a 110-cm-long baleen “frond.”   

Key Reference:

Marshall, B.A. and Walton, K. Jan., 2021. Baleenopelta rotunda, a newly discovered limpet from decaying baleen from New Zealand. Molluscan Research. Published online.  

RATTLESNAKES: From the Perspective of a Southern California Field Geologist.

During my nearly 45+ years of geologic mapping and associated fossil collecting, especially in the San Gabriel Mountains in Southern California just north of Los Angeles, I have been always been acutely aware that rattlesnakes are a constant hazard. 

My sightings of rattlesnakes during my field work have been “uncommon.” This post focuses on some of the rattlesnakes that I encountered and photographed. 

All of the following images, except the two are Crotalus atrox, the Southern Pacific rattlesnake. Most of these snakes that I have encountered were about two feet long (estimated), have a reddish gray "diamondback" pattern along their backbone, and have two grayish stripes on their cheeks.

IMAGE 1: On a road, 4 pm, cool and windy, May 30, 2011.

IMAGE 2: On a hiking trail, 10 am, warm, April 4, 2008.

IMAGE 3: Off-trail in a very remote area, warm, October 1, 2006. The visible part of the "Jacob Staff" (a measuring stick) is about 6 inches in length.

IMAGE 4: On a road, moderately warm, 9:30 am.

IMAGE 5: On a road 4 pm, August 2011. This snake is the longest rattlesnake (about 4 feet long) that I have ever seen (about 4 feet long) in the field. I identify it as Crotalus helleri, which has many snynonyms, including C. oreganus helleri, and C. viridis helleri. It is black with some white or yellow small spots (dots) aligned in widely spaced rows. The venom of this snake is highly toxic to humans and occasionally fatal.

IMAGES 6 and 7: Hiking trail with a steep dropoff just to the left, June 8, 2011, warm, 10 am. The snake is hidden in the black “hole” in the grass. The next image is a closeup of the black “hole.” I was never able to see the snake very well. It was black, and it might have been another Crotalus helleri.

The last two images bring to mind a very important lesson: NEVER WALK SIDE-BY-SIDE with another person when in the field. Always walk in a single-file. If you were walking side-by-side with someone situation like this one, it is likely that one of you would be walking in the grass. That person would have most certainly stepped on the snake.