Download - Cultural Ecology of the Queen Conch

Transcript
Page 1: Cultural Ecology of the Queen Conch

Cultural Ecology of the Queen Conch

Strombus gigas

(Class Gastropoda)

Page 2: Cultural Ecology of the Queen Conch

Other Conch Species

• Florida Crown

• Florida Fighting

• Florida Horse

• Hawking

• Milk

• West Indian Crown

• West Indian Fighting

Page 3: Cultural Ecology of the Queen Conch

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

Page 4: Cultural Ecology of the Queen Conch

Mr. Slimy

Page 5: Cultural Ecology of the Queen Conch

Want to Know How the Shell Develops?

Page 6: Cultural Ecology of the Queen Conch

Talk to Kira

Page 7: Cultural Ecology of the Queen Conch

Habitat and Feeding Habits

• Seagrass beds

• Eats grasses, epiphytes and detritus

• Have you seen a conch on our dives?

• How big?

Page 8: Cultural Ecology of the Queen Conch

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

Page 9: Cultural Ecology of the Queen Conch

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)

Page 10: Cultural Ecology of the Queen Conch

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

Page 11: Cultural Ecology of the Queen Conch

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)

Page 12: Cultural Ecology of the Queen Conch

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)

Page 13: Cultural Ecology of the Queen Conch

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)

Page 14: Cultural Ecology of the Queen Conch

The Conch in Mesoamerica

Archaeological and Ethnohistoric Evidence

Page 15: Cultural Ecology of the Queen Conch

Early Images

• Teotihuacan 0-700 AD

• Central Valley of Mexico

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

Page 16: Cultural Ecology of the Queen Conch

Coyote Playing Conch

Teotihuacan

Page 17: Cultural Ecology of the Queen Conch

Xochicalco

• Warring City States following the collapse of Teotihuacan

• Associated with the rain deity (Tlaloc?)

• Symbol of wealth

• Acquired by trade rather than conquest

Page 18: Cultural Ecology of the Queen Conch

Geometric Elaboration

Xochicalco

Page 19: Cultural Ecology of the Queen Conch

The Mexica

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

(Tlaloc/Huitzilopochtli)

• Trade and tribute

• Protein sources highly prized

Page 20: Cultural Ecology of the Queen Conch

Conch Sculpture at the Templo Mayor

Tenochtitlan

Page 21: Cultural Ecology of the Queen Conch

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)

• No se puede comer La Patria