Sida crystallina

(O. F. Müller, 1776)

Sida crystallina is a freshwater cladoceran (ctenopod) in the Sididae. It is an epiphytic strongly associated with aquatic macrophytes, attaching to plant stems using adhesive secretions from the nuchal organ. The exhibits functional separation between locomotory and feeding appendages, with frequent swimming observed especially in juveniles. It has been documented across Europe and Asia, including detailed studies in South Korea and North America.

Sida crystallina by (c) Dmitry Kulakov, some rights reserved (CC BY), uploaded by Dmitry Kulakov. Used under a CC-BY license.

Pronunciation

How to pronounce Sida crystallina: //ˈsiː.də ˌkrɪs.təˈlaɪ.nə//

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Identification

Distinguished from other epiphytic cladocerans by stronger attachment to macrophyte stems via nuchal organ secretions. Typically found attached to emergent plant stems rather than free-swimming. Six pairs of serially similar trunk limbs represent plesiomorphic cladoceran traits. Body length correlates with filtering rate, with larger individuals showing higher rates.

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Habitat

Lentic freshwater with abundant aquatic macrophytes. Strongly associated with emergent plant stems, particularly in . Documented on Phragmites australis and Paspalum distichum in South Korean studies; also recorded on Nymphaea odorata in North American .

Distribution

Europe; South Korea (147 lentic freshwater bodies surveyed); North America (Michigan, USA). GBIF records indicate presence in Palearctic and Oriental (Indomalaya) regions.

Diet

consuming suspended particles <35 µm and epiphytic organic matter (EOM) on macrophytes. Stable isotope analysis confirms epiphytic organic matter as food source. Filtering rate decreases with increasing food concentration.

Host Associations

  • Phragmites australis - attachment substrateemergent stem surfaces used for attachment
  • Paspalum distichum - attachment substrateemergent stem surfaces used for attachment
  • Nymphaea odorata - attachment substrateleaf surfaces used for sampling in Michigan studies

Behavior

Attaches to macrophyte surfaces using adhesive substances secreted by the nuchal organ; attachment strength exceeds that of other epiphytic cladocerans. Swims frequently and well when disturbed, with juveniles moving between substrates more often than and occupying positions nearer the water surface. Reattachment sites located visually. movement patterns show limited variation compared to some littoral .

Ecological Role

Epiphytic consumer of organic matter on macrophytes; contributes to high diversity and abundance of epiphytic in complex macrophyte structures. Filter feeding activity processes suspended particulate matter in . influenced by food availability and fish .

Similar Taxa

  • SimocephalusAlso a filter-feeding cladoceran attached to plants, but Sida crystallina shows stronger attachment strength and more frequent swimming when disturbed
  • Chydorid CladoceraShare epiphytic but differ in feeding mode—chydorids are periphyton and detritus feeders correlated with diatom , whereas Sida is a not correlated with diatom density

More Details

Subspecies

Two recognized: Sida crystallina crystallina (O. F. Müller, 1776) and Sida crystallina americana Korovchinsky, 1979

Filtering rate equation

In situ filtering rate (VF, ml·animal⁻¹·d⁻¹) predictable from body length (L, mm) and concentration of small (<35 µm) suspended particles (Sn, mg·liter⁻¹ dry wt)

Sources and further reading