The aim of this study is to investigate the possibility of using the tensile strength and the elasticity as two, among others, objective criteria for the evaluation of the quality and commercial value of two ‘Elephant Ear’ commercial sponges (Mediterranean and Philippine). These criteria could also provide additional taxonomic characters for the distinction of ill-defined species. The average tensile strength of the Mediterranean Elephant Ear was found equal to 2.88 ±0.19 kg cm-2 and that of the Philippine Elephant Ear equal to 6.88 ±0.77 kg cm-2 while the corresponding values for elasticity were 26.1 ±0.79% and 7.8 ±0.6%. This difference is related to the structure and arrangement of the spongin fibres as seen under the scanning electron microscope. The arrangement of the secondary fibres (very compact and regular structure) as well as the abundance and the orientation of the primary fibres (arrangement in the form of bars perpendicular to the external surface) give to the Philippine Elephant Ear a higher tensile strength value, a roughness to the touch and consequently inelasticity and stiffness. In contrast, the large number of smooth secondary fibres in the Mediterranean Elephant Ear, their loose arrangement and the limited number of primary fibres give to this sponge a higher elasticity and a smaller tensile strength value.

There is very little documentation on the economic importance of locally available marine sponges (Porifera) in north-western Europe. From Iceland and the Faroe Islands there are records of naming and using the so-called mermaid's glove sponge (Isodictya palmata) especially for cleaning purposes. As late as in the 1940s, school children in the Faroe Islands gathered this sponge and used it to clean the slate.

In the present study, carried out in the Spermonde Archipelago, south Sulawesi, Indonesia, an assessment is presented of the farming potential of six sponge species (out of nine candidates considered) possessing pharmacologically promising compounds, i.e. Aaptos suberitoides, Amphimedon paraviridis, Callyspongia (Euplacella) biru, Hyrtios reticulatus, Ircinia ramosa and Pseudoceratina cf. verrucosa. A total of 350 cuttings was threaded on a polyethylene rope and attached to horizontal mooring structures at three experimental sites. Growth and survival were monitored for a period of six months and for some explants for an additional period of ten months. All cuttings were photographed at regular time intervals and growth was measured as increase in length and dry weight. With the exception of P. cf. verrucosa, survival rates were high (80–96%) during the mariculture period. Size increases were too little to be measured in A. suberitoides and P. cf. verrucosa cuttings. Significant growth was only observed for C. biru. The high growth potential and high survival rate of this sponge species suggest that it is a promising candidate for further mariculture development.

The palatability of organic chemical extracts from ten of the most abundant sponge species along the Israeli (shallow) coast, eastern Mediterranean Sea (Axinella sp., Axinella polypoides, Chondrilla nucula, Ircinia sp., Psammocinia sp. 1, Psammocinia sp. 2, Psammocinia sp. 3, Psammocinia sp. 4, Sarcotragus sp. and Tetilla sp.) was tested. To examine the generality of the phenomenon, it was evaluated with two types of potential predators, a fish and a gastropod. It was determined that the extracts of only two species (Psammocinia sp. 1 and Psammocinia sp. 3) deterred feeding of the omnivorous ornate Mediterranean wrasse Thalassoma pavo. On the other hand, extracts of five other sponges (Chondrilla nucula, Axinella sp., Ircinia sp., Sarcotragus sp. and Psammocinia sp. 2) were non-palatable to the omnivorous gastropod Strombus persicus (the extracts that deterred the fish did not deter the gastropod and vice versa). We also determined the capacity of extracts from six Red Sea sponges to deter T. pavo, and compared it with these extracts' effect on the Red Sea wrasse T. klunzingeri. All the extracts that deterred the Red Sea wrasse (from Amphimedon chloros, Crella cyatophora, Negombata magnifica and Theonella swinhoei) were also non-palatable to the Mediterranean wrasse. In addition to these four species, also Diacarnus erythraenus deterred Thalassoma pavo while being palatable to T. klunzingeri, whereas food pellets with extracts of Niphates rowi were eaten by both wrasse species.