Transcript The Queen Conch - Miami University

Cultural Ecology of the Queen
Conch
Strombus gigas
(Class Gastropoda)
Other Conch Species
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Florida Crown
Florida Fighting
Florida Horse
Hawking
Milk
West Indian Crown
West Indian Fighting
Anatomy
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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
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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:
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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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