Panopea zelandica
| Panopea zelandica | |
|---|---|
| |
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Bivalvia |
| Order: | Adapedonta |
| Family: | Hiatellidae |
| Genus: | Panopea |
| Species: | P. zelandica
|
| Binomial name | |
| Panopea zelandica | |
| Synonyms | |
|
Panopaea zelandica Quoy and Gaimard, 1835 | |
Panopea zelandica, commonly known as the deepwater clam or New Zealand geoduck, is a large species of marine bivalve mollusc in the Panopea (geoduck) genus of the family Hiatellidae.[1] It is also sometimes called a king clam, or a gaper – in reference to the shell not being closed at either end.
It is found around the North, South and Stewart islands and occurs mainly in shallow waters (5–25 metres) in sand and mud off sandy ocean beaches.[2] Another geoduck species, Panopea smithae, is found in deeper New Zealand waters.
Like other geoducks, P. zelandica burrows downwards in the mud and extends a siphon 30-45 centimetres up to the surface of the substrate. The siphon contains two tubes. Water is sucked down one tube, filtered for food and then expelled through the other.
Habitat
[edit]P. zelandica distribution is near the North, South, and Stewart Islands of New Zealand. Like many geoducks, they live in shallow, subtidal waters (5-25m), with a higher density around 15m.[3] They have also been found in mud flats as well. They, like many clams, are temperate animals, so the average water temperature is integral for their overall survival.[4] The average water temperature for these animals is between 11-19 degrees Celsius.[5][4]
Feeding
[edit]Like most bivalves, geoducks are filter feeders.[6] While there is not much information on the specifics of feeding for P. zelandica, other species in this genus use the siphon to pull water in through the water column where the buried bivalved shell resides. P. zelandica and other Panopeas consume mostly small particles and planktonic animals.[6][7]
Reproduction
[edit]Geoducks are broadcast spawners in the form of dribble spawning, so females will release "batches" of eggs (around 2 million) in a single spawning period.[8] Unlike other species like P. abrupta and P. generosa, P. zelandica only produces around 2 million eggs during their lifetime (compared to other species producing 2-10 million).[3] Females contain large ovaries that rest within the two halves of their shells. The sperm is also released into the water column as the eggs are being released.[9] This process typically takes place during the warmer months, as the temperature change triggers reproduction.[8] Many of the eggs that are released will not reach maturity, so the ratio of egg and sperm to fully grown geoduck, is low.[7]
Commercial fishing
[edit]Currently, the industry for commercially fishing P. zelandica in New Zealand, is small.[10] While the first few fisheries began in New Zealand in 1988, P. zelandica was not commercially harvested until recent years.[10][9] One of the notable reasons for this is because of the small population density of species in the area.[10] The geographical spread of P. zelandica also poses a problem to commercial fisheries. Because the population has not been documented and recorded as thoroughly as other species of geoducks, tracing this particular species in regards to commercial use has its limitations.[11] Thus, fishing P. zelandica has proven to be unsustainable naturally and to continue this practice, will need some form of man-made modifications.[10]
Geoduck fisheries are a very lucrative business in the Northern Pacific part of the United States, areas of China, South Korea, and Japan.[6][11] It is currently around an $80 million dollar business. The main part of the geoduck, its siphon, is what attracts millions of people worldwide. It can be eaten a variety of different ways (raw, sauteed, etc.) and is seen as a delicacy in some areas.[6]
Gallery
[edit]-
End-on view of Panopea zelandica's gape -
Inside view of Panopea zelandica shell
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References
[edit]- ^ Powell, Arthur (1979). New Zealand Mollusca. William Collins Publishers Ltd. ISBN 0-00-216906-1.
- ^ Deepwater (King) Clam fishery summary Archived 2008-10-14 at the Wayback Machine - New Zealand Ministry of Fisheries.
- ^ a b "Population abundance estimates of the New Zealand geoduck clam, Panopea zelandica, using North American methodology: is the technology transferable? - Free Online Library". www.thefreelibrary.com. Retrieved 2024-04-30.
- ^ a b Sharma, Shaneel S.; Alfaro, Andrea C.; Ragg, Norman L. C.; Zamora, Leonardo N. (February 2020). "Effects of temperature on early development of the New Zealand geoduck Panopea zelandica (Quoy & Gaimard, 1835)". Aquaculture Research. 51 (2): 751–760. doi:10.1111/are.14425. ISSN 1355-557X.
- ^ Sharma, Shaneel S.; Venter, Leonie; Frost, Emily J.; Alfaro, Andrea C.; Ragg, Norman L.C.; Zamora, Leonardo N. (11 August 2023). "Behavioural and physiological responses of juvenile geoduck (Panopea zelandica) following acute thermal stress". Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology. 269: 110892. doi:10.1016/j.cbpb.2023.110892. PMID 37573964.
- ^ a b c d "Geoduck". NOAA. April 3, 2024. Retrieved 2024-04-30.
- ^ a b "Geoduck". Oceana. Retrieved 2024-04-30.
- ^ a b Gribben, P. E.; Hay, B. E. (June 2003). "Larval development of the New Zealand geoduck Panopea zelandica (Bivalvia: Hiatellidae)". New Zealand Journal of Marine and Freshwater Research. 37 (2): 231–239. Bibcode:2003NZJMF..37..231G. doi:10.1080/00288330.2003.9517161. ISSN 0028-8330.
- ^ a b Breen, Paul A.; Gabriel, Claire; Tyson, Trish (September 1991). "Preliminary estimates of age, mortality, growth, and reproduction in the hiatellid clam Panopea zelandica in New Zealand". New Zealand Journal of Marine and Freshwater Research. 25 (3): 231–237. Bibcode:1991NZJMF..25..231B. doi:10.1080/00288330.1991.9516475. ISSN 0028-8330.
- ^ a b c d Gribben, Paul E.; Heasman, Kevin G. (March 2015). "Developing Fisheries and Aquaculture Industries for Panopea zelandica in New Zealand". Journal of Shellfish Research. 34 (1): 5–10. doi:10.2983/035.034.0103. ISSN 0730-8000.
- ^ a b Gribben, Paul E; Millar, Russell B; Jeffs, Andrew G (July 2014). "Fertilization success of the New Zealand geoduck, Panopea zelandica : Effects of sperm concentration, gamete age and contact time". Aquaculture Research. 45 (8): 1380–1388. doi:10.1111/are.12085.