SECTIONED GASTROPOD SHELLS: MORE THAN MEETS THE EY

SECTIONED GASTROPOD SHELLS: MORE THAN MEETS THE EYE

Many years ago, while at a commercial-shell dealer in southern California, I came across some marine gastropod shells that had been sectioned (= cut/sliced”) vertically. I bought a few, put them in a picture frame, and hung the frame in my office. Sectioned shells have their own beauty. Some can be easy to recognize as to what the original genus and species are, but some are more challenging and require some knowledge of shell morphology vs. families/genera. 

I decided to post an image of my frame containing the sections (identified for your benefit) and also decided to include another image, showing what the original shells looked like.

Sectioned Shells: Starting at the top left, "moving" in a clockwise position:

Pleuroploca trapezium (Linnaeus, 1758)

   Family Fasciolariidae

   Indo-Pacific region, shallow marine, lives under corals.

   This specimen is 14.5 cm in height.

   Tibia delicutaula? (Nevill, 1881)

   Family Strombidae

   Arabian Sea. Deep water, moderately rare.

   This specimen is 9.5 cm in height.

    Lambis scorpius (Linnaeus, 1758)

   Western Pacific, lives in coral-reef areas.

   This specimen is 14.5 cm in height.

    Turritella cerebra

   Family Turritellidae

   Indo-Pacific region, shallow marine.

   This specimen is 10.5 cm in height.

What The Non-sectioned Shells [of the same species illustrated above] Look Like:

These figures are also arranged clockwise (starting in the upper left corner), as in the preceding figure.

When I recently checked online, I found the following site where sectioned shells (very affordable) are for sale:

Seashell Supply and Emporium:  seashellsupply.com

(located in Camarillo, southern California) 

You can purchase sectioned shells (as well as complete shells) at other locations near you (check the internet). 

THE BLUE CORAL SNAKE

While researching my last post about “Blue Coral,” I came across the topic “Blue Coral Snake.” The latter has nothing to do with "Blue Coral," but this snake does belong to the family that includes the strikingly banded and venomous "coral snakes" that live around and in coral reefs. The Blue Coral Snake, which lives in jungles, has electric blue stripes and a neon-red head. Its slender body, which can be up to 5 feet long, is blue/black with cobalt blue scales. Its tail and belly can be orange. All of this vibrant coloration serves as a warning to predators.

The "Blue Coral Snake."

The Latinized name of this snake is Calliophis bivirgatus. It lives in dense rainforests at 300 to 3,600 feet elevation, in southeast Asia (Malaysia, Burma, Thailand, Indonesia, and other neighboring regions). This snake is venomous, and its venom is extremely potent. It can cause paralysis and respiratory failure. Calliophis bivirgatus belongs to the family Elapidae, which includes cobras and sea snakes. The blue coral snake can prey on young king cobras. 

The blue coral snake is timid and primarily nocturnal. It eats other snakes, as well as small lizards. Its has specialized teeth that curve backward, thereby holding onto its prey. It venom glands, which are located behind its eyes, are the biggest venom glands in the world. Its venom can be fatal to humans, and there is currently no anti-venom. This venom is like that of most other deadly snakes, it that it  can cause its prey to instantly freeze with muscle spasms (cramps). Its venom is similar to that of some spiders and scorpions, as well as to cone snails (e.g., Conus geographus---see my April 22, 2019 blog post on “Cone shells Past and Present.”

This snake has a defensive position that mimics cobras, i.e. its flattens the neck and raises its forebody off the ground. Females are larger than the male. This snake can live up to 20 years.

References Consulted

facts.net/nauture/animals

businessinsider.com/blue-coral-snake-venom

 

“THE BLUE CORAL”

This animal, known scientifically as Heliopora coerulea (Pallas, 1766), is an extant octocoral with a massive skeleton (up to a meter in diameter that can be columnar, plate-like, or branched). The blue color of its skeleton is often obscured by the brownish to gray-brown color of its living tissues. The skeleton itself contains iron salts that produce its unique blue color. Furthermore, the skeleton consists of fibrocrystalline aragonite (a type of calcium carbonate). It is a hermatypic zooanthellaete species with polyps in the skeleton. Each polyp has eight tentacles.

Heliopora colonies are variable in their shape, ranging from branching forms (with blunt ends) to encrusting forms.

Heliopora coerulea: 8.5 inches [21 cm] wide and 6 inches [15.2 cm tall], from the Philippines. 

Close-up of a part of the specimen of H. coerulea shown above.

The surface of the skeleton is smooth and perforated by cylindrical pits of two sizes: 1) widely-spaced “tiny black holes” up to 0.25 mm diameter and encircled by a stellate margin and 2) much smaller tubular-shaped openings used by the autozooids (part of the internal canal system that contains the zooanthellae = the symbiotic algae).

An even more close-up of the same specimen of H. coerulea shown above. Notice the two different sizes of openings in the skeleton: the autozooids = black holes (each one up to 0.25 mm diameter and encircled by a stellate margin) and the much smaller (near microscopic size) tubular openings that, according to Wood (1983) enclosed extensions of the internal-canal system that contained the zooxanthellae.

Heliopora coerulea is a species that can tolerate thermal changes. It has a fossil record since the Cretaceous. The morphology of this octocoral has changed little since then.

The geographic occurrence today of H. coerulea is confined to the tropics: Indian Ocean and western Pacific Ocean, including the Japan and the Great Barrier Reef of Australia. It lives nearshore on reefs, in depths below two meters. It is a vulnerable species.

Its classification is: 

Phylum Cnidaria

Subphylum Anthozoa

*Class Octocorallia (lack true septa)

Order Helioporacea (includes only one genus: Heliopora)

Family Helioporidae

Genus Heliopora

Species H. coerulea

**Species H. hiberniana

In addition to the “Blue Coral,” octocorals include soft corals (such as Tubipora = the red-colored organ-pipe coral), sea pens, and gorgonians (sea fans and sea whips). There are about 3,000 known species of octocorals. They have colonial polyps with eight-fold symmetry (note: true corals have hexa-radial symmetry).

Zoe et al. (2018) reported a new species of living Heliopora, namely H. hiberniana, from offshore areas in north Western Australia. It differs from the “Blue Coral” by having a white skeleton, more slender branches, and some differences in skeletal morphology.

References Cited or Used:

en.wikipedia.org/wiki/Blue_coral

gbif.org/occurrence/1039258522

   [this online site is via the Invertebrate Zoology Division, Yale Peabody Museum]

Wood, E. M. 1983. Corals of the world. T.F.H. Publications. Neptune City, New Jersey, 256 pp.

Zoe, T.R., and seven others. 2018. Integrated evidence reveals a new species in the ancient blue coral genus Heliopora (Octocorallia). Scientific Reports 8, article no. 15875.