Periwinkles, scientifically known as Littorina sp., are diminutive whelks or sea snails that inhabit the intertidal zone. Their favoured habitats encompass tide pools, rocky shores, and even muddy environments such as estuaries and mangroves. This family of gastropod mollusks boasts a staggering array of over 200 distinct species, showcasing a truly global distribution.
Feeding primarily on algae and small invertebrates that thrive within these ecosystems, periwinkles employ a distinctive anatomical structure called a radula. This tongue-like, toothed apparatus is exclusive to mollusks and aids in the collection of sustenance by grazing and scraping algae off rocks.
Reproduction within this species is accomplished through egg-laying. Following internal fertilisation, the females release egg capsules into the ocean, each containing a sizeable quantity, ranging from 10,000 to 100,000 eggs. Subsequently, these eggs hatch into larvae, which then enter a planktonic phase, susceptible to the influence of currents and tides. Gradually, they settle on the ocean floor and eventually migrate to the intertidal zones where they establish their new home.
Remarkably, these tiny whelks constitute a popular food source for coastal inhabitants. Notably, the UK, Ireland, and Belgium in Europe demonstrate the highest consumption rates of this seafood variety. Harvested manually during low tides, these mollusks are cooked and enjoyed as delectable snacks. In various African and Asian culinary traditions, they are considered delicacies. Additionally, they serve as effective fish bait, with their shells removed to entice smaller fish species.
The captivating realm of marine wildlife is not exclusive to underwater exploration through scuba diving. Fascinating species can also be documented through marine wildlife videography and photography. These endeavours extend beyond submersion, encompassing the intertidal zones, including beaches and tide pools, which harbour a diverse array of captivating creatures. Filming these non-submerged areas holds pivotal importance in crafting compelling marine wildlife documentaries, demanding distinctive approaches and filming techniques to accurately capture their beauty on film.
Within this context, a specific technique was employed in the creation of a short video clip, showcasing the enchanting but often overlooked movements of seemingly stationary periwinkles. This technique, known as time-lapse, was utilised to magnify the remarkably slow movements of these creatures.
Time-lapse involves the manipulation of frame rate frequency. Instead of capturing the conventional number of frames per second, the camera records at a significantly reduced frame rate, such as one frame per second. When this footage is subsequently played at regular speed, an illusion of time acceleration is created, effectively hastening the depicted events. This accelerates the footage by 24 times (following cinematic standards), 25 times (in PAL systems), or 30 times (in NTSC systems), compared to the usual pace.
In contrast to slow-motion filming, which elevates frame rates to slow down the motion of fast-moving subjects, time-lapse is employed here to accentuate the typically languid movements of periwinkles. This technique infuses vitality into the seemingly inert motions, rendering them far more dynamic and visually compelling. Consequently, the snails' leisurely movements are exhibited at a staggering 48 times their actual speed, providing viewers with a fresh perspective on their activity.
Other post about marine life of the intertidal zone:
For an in-depth description about Rockskippers please go to our vlog post 1 https://www.beyondscuba.com/post/rockskippers
For an in-depth description about Fiddler Crabs please go to our vlog post 39
and vlog post 160
and vlog post 172
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