A skeleton‐less sponge ofCaribbean mangroves: invasive or undescribed?

Abstract

Recent surveys of sponges occurring on Caribbean mangrove roots demonstrated the presence of a skeleton‐less sponge of the genus Halisarca, very similar in its morphology to the temperate H. dujardinii. This study evaluated the possibility that the mangrove sponge was actually H. dujardinii that had been introduced into the Caribbean mangroves. Detailed histology revealed differences between the mangrove sponge and H. dujardinii in cuticle thickness, and in characteristics of the choanocytes, spherulous, and granular cells. Also, phylogenetic reconstruction and genetic distance estimates based on cytochrome oxidase I gene sequences clearly differentiated the mangrove Halisarca sp. from H. dujardinii. Therefore, we rejected the hypothesis of the invasion of H. dujardinii, recognizing instead the mangrove Halisarca sp. as a new species and naming it H. restingaensis sp. nov. Estimated levels of genetic variation in the ribosomal internal transcribed spacers indicated that populations of H. restingaensis sp. nov. are highly differentiated between Venezuela and Panama (Fst=0.71). This level of population differentiation is consistent with the short larval competence period that is common in members of the genus Halisarca.

Spherulization as a process for the exudation of chemical cues by the encrusting sponge C. crambe

“…C. crambe is a very common encrusting sponge and it has recently been proposed that its distribution has extended into the Macaronesian archipelago after frequent exchanges between these maritime areas 45 . Several other sponge species, most of them encrusting, have recently been described as invasive of various marine ecosystems 46 47 increasing substrate coverage by sponge worldwide and in particular in coral reefs 48 49 50 . Among the factors that could explain this expansion, climate change is likely to induce long-term shift in coral reef ecosystems towards a sponge and/or macroalgae-dominated ecosystems 51 52 .…”

Variation in fouling assemblages associated with prop roots of Rhizophora mangle L. in the Caribbean: The role of neutral and niche processes

“…2010; Alvizu et al. 2013). All these findings indicate that local spatial patterns of distributions might be the results of a combination of neutral dynamics and niche processes.…”

“…among roots) can be explained by supply-side processes and their repercussions on colonisation and subsequent densitydependent biological interactions (Guerra-Castro & Cruz-Motta 2018), whereas regional differences can be explained mainly by environmental filtering (mainly salinity and supply of energy/nutrients). Nevertheless, endemism could also explain a small fraction of patterns at the regional scale, as a few species, especially some species of sea squirts and sponges, appear to be endemic to LRNP (Rocha et al 2010;Alvizu et al 2013). All these findings indicate that local spatial patterns of distributions might be the results of a combination of neutral dynamics and niche processes.…”

<p>Appendix B, Table A2<br />From Primary Cell and Tissue Cultures to Aquatic Invertebrate Cell Lines: An Updated Overview</p> <p>&nbsp;</p>

“…It is, therefore, of great interest to illuminate the mechanisms driving the highly coordinated behaviours of ASCs in specific symbioses, such as the unipotent bacteriocyte stem cells that continuously proliferate to produce new bacteriocytes in some annelids (Bright and Giere 2005); the maintenance of symbiosis during the continuous bacteriocyte formation from aposymbiotic neoblasts in adult paracatenulid flatworms (Dirks et al 2012); the epithelial stem cells that actively shape the microbial intracellular communities in Hydra (Fraune et al 2009); or the larval bacteriocytes that develop from uninfected putative stem cells in the rice weevil Sitophilus oryzae (Alvizu et al 2013). Thus, cytosymbiosis-borne ASC phenomena are either established (in sponges) or supported (directly and indirectly; at least in Cnidaria, Platyhelminthes, Annelida, Arthropoda [insects and crustacean alike], Urochordata and Vertebrata).…”