Taxonomy and Ecology of Sponge‐Associate Marionina spp. (Clitellata: Enchytraeidae) from the Horomatangi Geothermal System of Lake Taupo, New Zealand

Abstract

The dissection of Heterorotula sponges collected in an area of geothermal activity at 126-145 m depth on the floor of Lake Taupo revealed a dense population of associated Enchytraeidae. They represent three species of Marionina, two of which known but exotic (the Palaearctic M. riparia BRETSCHER, 1899 and the Chinese M. seminuda XIE and ROTA, 2001), and one new to science, M. spongicola sp. n. This is the first report of an ecological association between enchytraeids and poriferans in the lake profundal zone. The possible nature of such relationship (casual contact for feeding or dwelling for food and shelter) is discussed.

Phylum Porifera

“…Freshwater sponges can survive extreme environmental constraints ranging from ice to cold and hot water, desiccation, silty floods, anoxy, eutrophy, and high concentrations of chemicals, hydrocarbons, and heavy metals (Old, 1932;Jewell, 1935Jewell, , 1939Sarà and Vacelet, 1973;Harrison, 1974Harrison, , 1977Rader, 1984;Rader and Winget, 1985;Van Soest and Velikonja, 1986;Willenz et al, 1986;Francis and Harrison, 1988;Ricciardi and Reiswig, 1993;Richelle-Maurer et al, 1994a,b;Vacelet, 1994;Reiswig and FIGURE 8.13 Reproductive strategies of most Spongillina display both K and r phases. Miller, 1998;de Ronde et al, 2002;Rota and Manconi, 2004;Müller et al, 2007). On the contrary, gemmule dispersal to colonize new habitats (A′-A′′-A′′′-A′′′′) matches the r phase when unsuccessful events (x) occur (right).…”

The Effects of Habitat Heterogeneity at Distinct Spatial Scales on Hard-Bottom-Associated Communities

“…Biological substrates can influence the composition and structure of the associated fauna by its architecture [8], the amount of sediment accumulated on it [12,44], the protection it offers against predators [13,45], shelter from extreme physical condition [46,47] and the provision of food resources [10]. In the current study, sponge communities were differentiated by the occurrence of meiofaunal oligochaetes, which are ectocommensals of sponges [48,49]. Oligochaetes inhabiting such filter-feeding organisms benefit from being in an environment with intense water flowing, ensuring high oxygen availability and food (microorganisms and organic detritus), and a lower exposure to the variable conditions of free sediments [48].…”

Fauna Europaea: Annelida - Terrestrial Oligochaeta (Enchytraeidae and Megadrili), Aphanoneura and Polychaeta

“…According to Brinkhurst (1994), the two families would be sister taxa; however, a comprehensive molecular analysis has failed to recover any close relationship between them (Erséus et al 2010). Ovary organization and oogenesis are also stated to differ between the two families (Gorgoń et al 2015), but the comparison should be extended to include more representatives of enchytraeids (for instance, Rota and Manconi 2004 reported different types of ovary organization among enchytraeid species of Marionina ).…”