Panamic Horse Conch Shell, Triplofusus princeps
Panamic Horse Conch and Panamic Horse Conch Shell, Triplofusus princeps. Provided by the Commercial Fishermen of the greater Los Cabos area, Baja California Sur, December 2009. Size: 31 cm (12.2 inches) x 13 cm (5.1 inches).
Panamic Horse Conch, Triplofusus princeps. Underwater photograph taken in Zihuatanejo Bay, Guerrero, November 2018. Photograph courtesy of Ron Woheau, Zihuatanejo.
Panamic Horse Conch, Triplofusus princeps. Underwater photograph taken in coastal waters off Puerto Vallarta, Jalisco, September 2021. Photograph courtesy of Kevin Erwin, Seattle, Washington. There are more than a dozen live shells shown in this photograph.
Phylogeny: The Panamic Horse Conch Shell, Triplofusus princeps (G.B. Sowerby I, 1825), is a member of the Fasciolariidae Family of Spindle, Horse Conchs and Tulip Shells. The genus Triplofusus is one of sixty-eight genera in this family, and there are two species in this genus. They are also known as the Panamanian Tulip Snail and the Prince Horse Conch Shell. In Mexico they are known as Tulipàn Principe and Concha Caballo.
Description: The Panamic Horse Conch Shell has a large body whorl, a high spire, a long open canal, and a large aperture. The exterior of the shell is sculpted with fine ridges spiraling along the whorls. Knobs mark the top edge of the lower whorls. The exterior of the shell is orange-brown. The interior is reddish-orange or salmon. The periostracum is dark brown. They have a rigid, leathery, operculum, which is marked with furrows. The foot of the living animal is brilliant red, with bright blue spots. The Panamic Horse Conch shell is the largest conch in the region reaching a maximum of 50 cm (19.7 inches) in length and 21 cm (8.3 inches) in height.
Habitat and Distribution: Panamic Horse Conch Shells reside in sand and rock environments in the intertidal zone, and at depths up to 41 m (135 feet). They are a tropical Eastern Pacific species. In Mexican waters they are found throughout the Gulf of California and range south the Guatemala. They are considered to be absent from the entire west coast of the Baja Peninsula, however the shell photographed above was collected from the extreme southwest coast of the Baja Peninsula.
Ecology and Behavior: Panamic Horse Conch Shells are a poorly studied and understood species. There is very limited documentation of their diet, predation, reproduction or ecosystem interactions. The similar looking other species in this genus, the Florida Horse Conch, Triplofusus giganteus, is a predatory carnivore that feeds on bivalves and other gastropods. They are gonochoric and reproduce sexually, with internal fertilization. The eggs are laid in sticky string-like masses. There is no mention in the available literature of this species engaging in any types of parasitic, commensal, or symbiotic relationships, however, when they are dead, their shells provide excellent homes for large hermit crabs, such as the Big Claw Purple Hermit Crab, Petrochirus californiensis. This species is edible and is harvested commercially. From a conservation perspective they have not been formally evaluated however they are fairly common with a relatively wide distribution and should be consider to be of Least Concern.
Synonyms: Fasciolaria acutispira, Fasciolaria crocata, Fasciolaria princeps, Pleuroploca acutispira, and Pleuroploca princeps.