Distribution and symptoms of epiphyte infection in major carrageenophyte-producing farms

Abstract

High density commercial farming of carrageenophyte Kappaphycus alvarezii is often plagued with "iceice" disease and epiphyte infection, which eventually leads to reduced production and in some cases collapse of crop. Epiphyte outbreak has been occurring regularly in major carrageenophyte farms in the Philippines, Indonesia, Malaysia and Tanzania. Infected materials from these countries were studied to establish baseline information on the epiphyte's identity, density, symptoms and secondary infection on the host seaweed. The causative organism was identified as Neosiphonia apiculata (Hollenberg) Masuda et Kogame, based on its morphological features. Epiphyte density on host seaweed materials decreased in the following order: the Philippines (88.5 epi cm −2 ), Tanzania (69.0 epi cm −2 ), Indonesia (56.5 epi cm −2 ) and Malaysia (42.0 epi cm −2 ). Initial symptoms were the presence of tiny black spots, indicating the embedded tetrasporeling in seaweed cortex layer. Vegetative form emerged after 2 weeks measuring less than 0.5 mm in length with a density of less than 25.0 epi cm −2 . Upon maturation, infected seaweed takes on a "hairy" appearance with "goose-bumps" like cortical swellings. The epiphyte appears as a solitary plant with multiple secondary rhizoids or as multiple epiphytes appearing from a single cortical opening. At the end of infection, the epiphytes left dark pits on the cortical swelling, and the carrageenophytes are infected by opportunistic bacteria. Bacterial enumeration of healthy and infected seaweed materials showed an increase of more than 300% in total bacterial count on infected materials dominated by Alteromonas sp., Flavobacterium sp. and Vibrio sp.

Chemical interactions between marine macroalgae and bacteria

“…The extensive farming of brown, red and green macroalgae in Asia has shown that all are susceptible to disease (Craigie & Correa 1996). In aquaculture, secondary bacterial infections contribute to disintegration of the infected tissue, finally leading to thallus rupture, breaking-off of macroalgae from culture lines and massive biomass loss (Vairappan et al , 2008. Infectious diseases in macroalgae might be highly destructive as in the case of the green spot rot of Undaria spp.…”

Epiphytic and Ice-ice Diseases of Seaweed, <i>Kappaphycus alvarezii</i> and its Effect on Growth Rate and Carrageenan Quality

“…Epiphytic disease is one disease parasite on seaweed that can cause crop failure. The disease is caused by parasite Neosiphoniaapiculata, (Vairappan et al, 2008), also due to drastic changes in salinity and temperature (Vairappan, 2006). Epiphytic infection can occurred on the entire surface thallus of seaweed (Figure 1).…”

Seaweed cultivation on the Southern and Southeastern Brazilian Coast

“…The former was caused by drops on salinity and an increase in temperature and the latter (goose pump) by bacteriological infection after epiphitism by Neosiphonia apiculata (Hollenberg) Masuda et Kogame , Vairappan et al, 2008.…”