Cultural Ecology of the Queen Conch Strombus gigas (Class Gastropoda)

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Cultural Ecology of the Queen Conch Strombus gigas (Class Gastropoda)
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Transcript of Cultural Ecology of the Queen Conch Strombus gigas (Class Gastropoda)

Cultural Ecology of the Queen Conch

Strombus gigas

(Class Gastropoda)

Other Conch Species

• Florida Crown

• Florida Fighting

• Florida Horse

• Hawking

• Milk

• West Indian Crown

• West Indian Fighting

Anatomy

• Shared with other gastropods (stomach-footed)• Reaches 30 cm in length• Mature conch has flared lip• Shell spines help reduce predation

– Larger shell

– Distributes crushing pressure over surface of shell

– Attachment device for epibionts to conceal shell

Mr. Slimy

Want to Know How the Shell Develops?

Talk to Kira

Habitat and Feeding Habits

• Seagrass beds

• Eats grasses, epiphytes and detritus

• Have you seen a conch on our dives?

• How big?

Juveniles

• Juveniles bury selves to escape predation, until ≈ 5 cm (Iverson et. al. 1989)

• Prime juvenile habitat:– Intermediate density of seagrass (30-80 g dry wt/m2 )

– 2-4 meters

– Strong tidal currents

– Most seagrass beds cannot support juveniles

Reproduction and Life Cycle

• Internal fertilization• Metamorphosis from larvae triggered by low

molecular weight compounds associated with red algae (Boettcher & Target 1997)

• Variations in shell development appear to be influenced more by local environment than genetic variability (Martin-Mora & James 1995)

Research

• Approximately 230 published papers by 1997

• Publication driven mainly by maricultural concerns

• Formal descriptions of larval stage of several Strombus species first appeared in 1993

Threats

• Over-”harvested” for…– Food

– Shell used for jewelry and decoration

• Productive areas become “sinks”

• Only 5,000-9,000 in Florida

• Fishing restrictions– Fishing moratorium in Florida since 1985 (little to no recovery,

relies on unpredictable current?)

– Bahamas restricted to free diving (unfortunately, juveniles and young adults are in the shallows)

Future

• Hatcheries producing millions of juveniles, but survival rate very poor compared to wild (Xanthid crabs a major predator of juveniles)– Thinner shells, shorter spines, low burial frequency

• Substrate enclosure? (Iverson et. al. 1989)

• May need higher density for males and females to detect one another (internal fertilization)

• Must begin to take a metapopulation perspective (Stoner 1997:21)

An Hypothesis Based on Info from Jyl

• Given that a colony of Conch will vacate an area once removed from that colony (Lapachin 1999), and…

• That under “natural” conditions there is much less predation of the adult vs. juvenile conch, then…

• Perhaps human predation has the double effect of not only removing a single conch, but also reducing survival of others due to energy-loss (= bears in the wild)

The Conch in Mesoamerica

Archaeological and Ethnohistoric Evidence

Early Images

• Teotihuacan 0-700 AD

• Central Valley of Mexico

• An empire’s symbol of control over distant ecological zones

Coyote Playing Conch

Teotihuacan

Xochicalco

• Warring City States following the collapse of Teotihuacan

• Associated with the rain deity (Tlaloc?)

• Symbol of wealth

• Acquired by trade rather than conquest

Geometric Elaboration

Xochicalco

The Mexica

• Ceremonial uses– cardinal directions– Tlaloque– maintain seasonal balance, duality

(Tlaloc/Huitzilopochtli)

• Trade and tribute

• Protein sources highly prized

Conch Sculpture at the Templo Mayor

Tenochtitlan

Is there anything to learn from Mesoamerican civilizations?

• Not just balance in modern sense, but integration of humans & the rest of the “natural” world

• Vs. the natural/cultural approach, managed/wild• Sanctions for violating life (human sacrifice),

enculturation processes which produce a sense of awe and symbiotic pleasure (Nahua)

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