Pleurotomella frigida

Pleurotomella frigida
Original image of a shell of Pleurotomella frigida
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
Subclass:	Caenogastropoda
Order:	Neogastropoda
Superfamily:	Conoidea
Family:	Raphitomidae
Genus:	Pleurotomella
Species:	P. frigida
Binomial name
Pleurotomella frigida Thiele, 1912
Synonyms
Pleurotomella (Anomalotomella) frigida Thiele, 1912

Pleurotomella frigida is a species of sea snail, a marine gastropod mollusk in the family Raphitomidae. This species was first described by Johannes Thiele in 1912. It is known for its distinct shell morphology and its occurrence in specific marine environments, particularly in the cold waters of the Antarctic region.

Description

The shell of Pleurotomella frigida is relatively small, with a length that varies between 5.2 mm and 11 mm. The shell is characterized by its elongated, fusiform shape and intricate patterns. The coloration of the shell can vary, but it typically features a combination of light and dark hues that provide camouflage against the seabed. The surface of the shell is adorned with fine spiral ridges and grooves, which add to its intricate appearance. The aperture is narrow, and the outer lip is thin and slightly flared.

The shell's structure is adapted to its marine habitat, providing protection against predators and harsh environmental conditions. The species exhibits a high degree of morphological variation, which is common among marine gastropods and is influenced by environmental factors such as water temperature, salinity, and substrate type.

Distribution

This marine species occurs in the Davis Sea and the Weddell Sea, Antarctica, particularly in the Davis Sea and the Weddell Sea. These regions are known for their rich marine biodiversity and complex oceanographic conditions. The species inhabits deep-water environments, typically at depths ranging from 200 to 600 meters. The cold, nutrient-rich waters of these regions provide an ideal habitat for Pleurotomella frigida, supporting its growth and reproduction.

The distribution of Pleurotomella frigida is influenced by various oceanographic factors, including currents, temperature gradients, and the availability of suitable substrates. The species is often found in association with other deep-water marine organisms, forming part of a diverse and complex ecosystem.

Habitat and Ecology

Pleurotomella frigida is adapted to life in deep-water marine environments. It is a benthic species, meaning it lives on or near the seabed. The species is typically found on soft substrates such as mud and sand, where it can burrow and find food. Pleurotomella frigida is a carnivorous species, feeding on small invertebrates and detritus. It uses a specialized radula, a toothed, chitinous ribbon, to scrape food from surfaces.

The species plays an important role in the benthic ecosystem, contributing to the balance of predator-prey relationships and the recycling of organic matter. Its presence indicates a healthy and functioning deep-water ecosystem, as it is sensitive to changes in environmental conditions.

Taxonomy

• Kingdom: Animalia
• Phylum: Mollusca
• Class: Gastropoda
• Subclass: Caenogastropoda
• Order: Neogastropoda
• Superfamily: Conoidea
• Family: Raphitomidae
• Genus: Pleurotomella
• Species: P. frigida

Morphological Characteristics

Pleurotomella frigida exhibits a reproductive strategy typical of many marine gastropods. The species is dioecious, meaning that individuals are either male or female. Reproduction involves the release of eggs and sperm into the water column, where fertilization occurs externally. The fertilized eggs develop into free-swimming larvae, which eventually settle onto the seabed and metamorphose into juvenile snails.

The reproductive cycle of Pleurotomella frigida is influenced by environmental factors such as water temperature, salinity, and food availability. These factors can affect the timing and success of reproduction, as well as the survival and growth of the larvae.

Feeding and Behavior

Pleurotomella frigida is a carnivorous species, feeding on small invertebrates and detritus. The species uses its radula, a specialized feeding organ, to scrape food from the substrate. The radula is equipped with rows of tiny, chitinous teeth that can efficiently process a variety of food sources.

The feeding behavior of Pleurotomella frigida plays a crucial role in the benthic ecosystem, contributing to the recycling of organic matter and the maintenance of sediment health. By consuming detritus and other organic material, the species helps to break down and decompose these materials, releasing nutrients back into the ecosystem.

Predators and Defense Mechanisms

Pleurotomella frigida faces predation from a variety of marine organisms, including fish, crabs, and other predatory gastropods. The species has evolved several defense mechanisms to protect itself from predators. The shell provides a physical barrier, and its coloration and patterns offer camouflage against the seabed. When threatened, the snail can retract its body fully into the shell, using the narrow aperture and flared outer lip to seal itself off from potential threats.

In addition to these physical defenses, Pleurotomella frigida may also produce chemical compounds that deter predators. These compounds can be released into the water when the snail is disturbed, creating a chemical barrier that discourages predation.

Ecological Role

Pleurotomella frigida plays an important role in the marine ecosystem, contributing to the balance of predator-prey relationships and the recycling of organic matter. As a carnivorous species, it helps to control the populations of small invertebrates and detritus, maintaining the health and stability of the benthic environment.

The presence of Pleurotomella frigida in the ecosystem also provides a food source for a variety of predators, supporting the complex food web of the marine environment. The species' interactions with other organisms, both as a predator and prey, contribute to the overall biodiversity and stability of the ecosystem.

Human Impact and Conservation

The marine habitats of the Antarctic region, where Pleurotomella frigida is found, are subject to various anthropogenic pressures, including overfishing, trawling, and pollution. These activities can have significant impacts on the delicate ecosystems that support species like Pleurotomella frigida. Overfishing and trawling can disrupt the seabed, destroying habitats and reducing the availability of food sources. Pollution, particularly from plastic waste and chemical contaminants, can degrade water quality and harm marine life.

References

• Engl, W. (2012). Shells of Antarctica. Hackenheim: Conchbooks. 402 pp.

External links

• Thiele, Johannes. "Die antarktischen schnecken und muscheln." Deutsche Südpolar-Expedition (1901–1903) 13 (1912): 183-286 (Erich von Drygalski, E.v. ed.), vol. 8, No. 5, Georg Reimer, Berlin.
• Kantor Y.I., Harasewych M.G. & Puillandre N. (2016). A critical review of Antarctic Conoidea (Neogastropoda). Molluscan Research. 36(3): 153-206
• Tucker, J.K. (2004). "Catalog of recent and fossil turrids (Mollusca: Gastropoda)" (PDF). Zootaxa. 682: 1–1295. doi:10.11646/zootaxa.682.1.1.
• Griffiths, H.J.; Linse, K.; Crame, J.A. (2003). SOMBASE - Southern Ocean mollusc database: a tool for biogeographic analysis in diversity and evolution. Organisms Diversity and Evolution. 3: 207-213