Holmsella pachyderma - A red algal parasite of Gracilaria gracilis

This small, pale, whitish algae is a red algal species that is parasitic on Gracilaria gracilis, Slender Wart Weed and Gracilariopsis longissima.

Species found on the algae Gracilaria gracilis, Slender Wart Weed, on the lowershore at Great Hogus, Marazion, Cornwall. 02.10.16.

Parasitic red algae
Holmsella pachyderma
- in cross section 1

Parasitic red algae
Holmsella pachyderma
- with 0.01mm division rule 1

Parasitic red algae
Holmsella pachyderma
- outer edge of thallus 1

Parasitic red algae
Holmsella pachyderma
- outer edge of thallus 2

Parasitic red algae
Holmsella pachyderma
- tetraspores 1

Parasitic red algae
Holmsella pachyderma
- tetraspores 2

This parasitic red alga was found among plants of a fairly large colony of Gracilariopsis longissima, Long Wart Weed, west of Lariggan Rocks, Penzance, Cornwall. 31.08.18.

APHOTOMARINE supports open source data recording and sharing for the benefit of wildlife, recorders, research, science and education. The project recommends the following websites and works with the following bodies and organisations.

The Marine Biological Association or MBA, based in Plymouth, is one of the world’s longest-running societies dedicated to promoting research into our oceans and the life they support. Since 1884 the MBA has been providing a unified, clear, independent voice on behalf of the marine biological community.It has a growing membership in over 40 countries.

The National Biodiversity Network or NBN is a charity that supports open source data sharing and recording supporting conservation, science and education. "Why do recorders need open source?". Simply because it supports the core values of wildlife recording and the free use of records and data over a very wide network that includes partners like the Natural History Museum.

The taxonomy used here is based on that of the following database, which is also used by the MBA, NHM and the NBN.

The World Register of Marine Species or WoRMS.

AlgaeBase is a database of information on algae that includes terrestrial, marine and freshwater organisms.

APHOTOMARINE

An educational resource dedicated mainly to the photography and diversity of marine life that can be found in coastal waters and intertidal areas of Great Britain and Ireland by David Fenwick.

An educational resource dedicated mainly to the photography
and diversity of marine life that can be found in coastal waters
and intertidal areas of Great Britain and Ireland by David Fenwick.