Epiphytism of Gracilaria cliftonii (Withell, Millar & Kraft) from Western Australia

Abstract

Epiphytism in Gracilaria is a common phenomena observed in natural populations and under culture conditions. Generally, epiphytes are attached superficially to the surface of the host however, genera such as Polysiphonia spp. and Ceramium spp. can penetrate into the host tissue affecting its growth and hence productivity. The present paper aims to identify and quantify epiphyte abundance and characterise their attachment and penetration on the natural populations of Gracilaria cliftonii collected from Shoalwater Marine Park, Perth, Western Australia. G. cliftonii samples were collected monthly for 1 year and their epiphytes were identified. Histological studies of G. cliftonii were also performed on epiphyte attachment sites. Twenty-four species of macroalgae epiphytes were recorded, 21 belonging to Rhodophyta and 3 to Chlorophyta. Hypnea episcopalis and Polysiphonia forfex were the dominant (p<0.05) species during the sampling period. The maximum epiphytic load was observed in October (40%), however, the maximum diversity of epiphytes was recorded in September and February (n=14). Light and scanning electron microscopy studies of the epiphyte attachment sites revealed that P. forfex and Ceramium isogonum penetrated into the cortex and outer medulla of G. cliftonii, while Bryopsis plumosa and Laurencia clavata altered the cellular structure of the cell wall of G. cliftonii.

The Genus Cladophora Kützing (Ulvophyceae) as a Globally Distributed Ecological Engineer

“…). Unidentified Cladophora species were among the most common epiphytes on the subtidal rhodophyte Gracilaria cliftonii in Western Australia (Muñoz and Fotedar ).…”

“…Epiphytic Cladophora also co-occurred with Chaetomorpha on seagrasses in coastal Lake Illawarra in SE Australia (Rutten et al 2004). Unidentified Cladophora species were among the most common epiphytes on the subtidal rhodophyte Gracilaria cliftonii in Western Australia (Muñoz and Fotedar 2009).…”

Ecological Studies of Epiphytic Microalgae and Epiphytic Zooplankton on Seaweeds of the Eastern Harbor, Alexandria, Egypt

“…In fact, these literatures focused on the epiphytic macroalgal species (Rindi and Guiry, 2004;Muñoz and Fotedar, 2009;Kersen et al, 2011), whereas very few literatures dealt with epiphytic microalgae and/or epifauna. Tanaka et al (1984) conducted a study on epiphytic microalgal communities on Sargassum piluriferum and artificial seagrasses in Sargassum bed.…”

Unique distribution of epiphytic Neosiphonia harveyi (Rhodomelaceae, Rhodophyta) along sargassacean hosts

“…Surface tension and roughness can vary among regions of a host thallus (Rönnberg & Ruokolahti 1986), and such factors can be of critical importance when attempting to explain patterns of epiphyte zonation. Some species of epiphytes, including N. harveyi, penetrate rhizoids deeply into the host cortex, frequently reaching the medullary tissue, while other epiphytes attach to the surface without causing any host tissue damage (Leonardi et al 2006;Muñoz & Fotedar 2010). Because older parts of fucalean thalli are generally tougher than younger parts (Hemmi & Jormalainen 2002), substrate conditions may influence rhizoid penetration by N. harveyi, resulting in variable densities observed along the host thallus.…”