The 'pipe builder' snail was awarded the title of 'environmental engineer', in light of its contribution to the construction of rocky surfaces on the coastline and reducing their rate of weathering in an effective way. It came to the brink of extinction, but researchers from Ben Gurion University managed to discover some live snail shells on the Carmel beach
A close-up photo of the tube's shell openings. Photography by Ayelet Nir
Nature is an amazing thing. The waves of the sea erode the rocks and the snail "tube builder", as its name suggests, rebuilds them. how? The snails settle on the rocks, accumulating accumulations, and after the animal completes its life cycle, its shell remains inside the rock, giving it its unique shape. For thirty years, the population of beaver snails decreased and for a moment we thought they were completely extinct, but in a new study by Prof. Ariel Kushmaro and the Nature and Parks Authority, we found new living accumulations of the beaver snail on the Carmel beach! And this is wonderful news!
The 'pipe builder' snail was awarded the title of 'environmental engineer', in light of its contribution to the construction of rocky surfaces on the coastline and reducing their rate of weathering in an effective way. After three decades of a sharp decline in the snail population of this species in Israel and a real concern that it might become extinct, a research group from Ben-Gurion University of the Negev in collaboration with the Nature and Parks Authority was able to detect a renewed appearance of the snail on the Carmel beach. DNA samples taken indicated a genetic kinship of the snail also to snails from south of Lebanon. The research findings were published in the journal Mediterranean Marine Science.
The border between Israel and Lebanon is stormy and poses a security threat, but when it comes to nature, the borders between the countries blur. The same goes for the location of the Dendropoma snail, which has not been seen in our area for three decades and is considered an endangered species on the coasts of Israel and recently reappeared on the Carmel coast and was even identified as genetically close to the snail from south of Lebanon.
Along the Israeli Mediterranean coast, one of the significant rocky habitats is developing as a natural value for conservation. A unique rock formation created by two types of snails - "beaver tube" and a triangular snail, which settle on top of the kurkar rocks in the coastal area and form dense clusters. The skeletons of snails remain attached to the substrate after the animal dies. The level of the rocky surface was eroded as a result of the energy of the sea waves, but was also rebuilt by the snails, in a long and drawn-out process, layer by layer. Each generation grows on top of the previous generation, so the surface includes both live (occupied) and dead (empty) shells. Habitats of this kind have been documented in Israel from Masha HaNkara in the north, from Makmorat and Jaffa on the central coast and further south as far as Palmachim.
A visual survey conducted during December 2020 and February 2021 along the edges of the rocky surfaces in the Carmel Beach area revealed 195 live clusters of the snail 'tube beaver'. The survey was conducted using photographic documentation and measuring the size of each living stock found. DNA sequences taken by the researchers from tissue samples of the snails showed 99-100% identity to the sequences obtained from southern Lebanon. One of the hypotheses for the renewed presence of the snail clusters is that small clusters were able to survive and reproduce for a long time under a dense cover of oysters from the invasive species "Pharaoh's Mud" and when these suddenly disappeared in 2016 (for an unknown reason), a valuable settlement space on the edge of the gill tables became available again and the snails won again with the opportunity to expand.
A cornice in the table of the Gigod at Tel Nami. Photo by Orit Barnea
"After three decades of a sharp decline in the population of snails of the genus Dendropoma in Israel and a real concern for its continued existence, this study demonstrates the re-emergence of this species on the aggregation charts on the Carmel coast," he said Prof. Ariel Kushmaro, director of the Laboratory for Environmental Biotechnology at Ben-Gurion University of the Negev and one of the leaders of the research.
The research group included: Prof. Ariel Kushmaro, Dr. Orit Barnea and Dr. Michal Lidor-Naim from Ben-Gurion University of the Negev, Dr. Rami Zadok from the University of Haifa and Dr. Ruth Yehal from the Nature and Parks Authority.
The tuber survey was funded by the Nature and Parks Authority and the genetic research was supported by the Abram and Stella Goldstein-Goren Foundation, Ben-Gurion University of the Negev.
One response
I think you mean Kurkar rocks. I don't know how to find rocks in Karkur, but she sure doesn't sit on the beach.