Hörntanden

Hörntanden, also known as *Dentalium* or "tusk shells," are a group of small, elongated marine mollusks belonging to the class Scaphopoda. These creatures are characterized by their distinctive tubular shells, which resemble miniature elephant tusks, hence the German name *Hörntanden* ("horn teeth"). Their shells are typically translucent, often with a pink, orange, or white hue, and can vary in length from a few millimeters to several centimeters.

Hörntanden are primarily found in sandy or muddy ocean floors, buried head-down in sediment, where they filter feed on plankton and small particles using their extended, ciliated feeding organ called a captaculum. Their orientation allows water to flow through the shell, bringing food particles that are then captured and directed to their mouth. They are commonly found in shallow coastal waters but can also inhabit deeper oceanic environments.

These mollusks play a role in marine ecosystems as both prey and habitat providers. Some species are economically significant as curiosities or decorative items due to their unique shells, which are sometimes polished and used in jewelry or collectibles. However, they are not typically consumed by humans.

Hörntanden have a simple body structure with no distinct head or foot, relying instead on their shell for protection and movement through sediment. They reproduce sexually, with external fertilization occurring in the water column. Their larvae, known as veligers, drift freely before settling and developing into adult forms.

While Hörntanden are not widely recognized in popular culture, they are of interest to marine biologists and shell collectors. Their fossilized remains have been found in geological layers dating back millions of years, providing insights into ancient marine environments. Conservation efforts are generally not a major concern for Hörntanden, as they are widespread and not currently threatened by overharvesting.