Boomer
Well-known member
You have to look and take into account the "erosion" rate of the shell and is why I posted the pics I did. Fresh uneroded shells will look different.
Summary: The gastropods Stramonita haemastoma (Muricidae), Morula nodulosa (Muricidae), Leucozonia trap (Fasciolariidae), and Pisania auritula (Buccinidae), coexist in the intertidal rocky coastline of Brazil, forming a guild that operates sés arrested six or little mobility . The diets of the 4 species were quantitatively analyzed and compared with the abundance of prey in 3 different locations of the Canal of San Sebastian, Brazil. The distribution of predators was also studied. Indices of overlapping Schoener to diet and use of habitat have taken clear that there is a strong sharing of resources between these gastropods in the intertidal region. S. haemastoma and M. nodulosa explored mainly the areas of mediolitoral lower and higher respectively, while L.nassa and P. auritula preferably occupied the fringes of sublitoral. An analysis of diet indicated a marked degree of overlap of niche between the first pair of species, although they eat in different habitats and eat prey of different sizes. The 4 species exhibited broad diets. S. haemastoma consumed mainly molluscs, M. nodulosa explored small barnacles and shellfish, while L.nassa, and P. auritula ingested preferably barnacles large and poliquetos. The muricídeos showed low selectivity of prey exploring the majority of food items according to their availability in the environment. The sharing of habitat is as important as the sharing of food in the structuring of the guild of gastropods predators. Flexibility in the diet is an adaptive strategy under conditions of uncertainty over the site of recruitment of prey and predators, coupled with cycles of larval dispersal over long distances. The analysis of correlation between morphology and diet radular not produced significant results, indicating that the rádula structure is a conservative, remaining as a useful tool for determining systematic relationship between species, genera and families
Abstract: The gastropods Stramonita haemastoma (Muricidae), Morula nodulosa (Muricidae), Leucozonia trap (Fasciolariidae), and Pisania auritula (Buccinidae), coexist in Brazilian intertidal rocky shores, constituting a guild which exploits sessile or slow mobile prey. Diets of the 4 species were quantitatively analyzed and compared with prey abundance in 3 different sites of St. Sebastian Channel, SP, Brazil. Predator distribution was also studied. Schoener 's overlap indices for diet and habitat usage showed that there was strong resource partitioning among those gastropods in the intertidal. S. haemastoma and M. nodulosa mainly exploited the lower and upper midlittoral zones respectively, while L.nassa, and P. auritula preferentially exploited the sublittoral fringe. Diet analysis indicated a marked niche overlap between the first pair of species, although they fed in distinct habitats and ate prey of different sizes. The 4 species exhibited a broad diet. S. haemastoma consumed mainly molluscs, M. nodulosa exploited small barnacles and bivalves, whereas L.nassa, and P. auritula ingested preferentially large barnac1es and polychaetes. The muricids showed low prey selectivity exploiting the majority of prey according to their availability in the environment. Habitat partitioning is as important as food partitioning in structuring this predatory gastropod Guild. Diet flexibility is an adaptive strategy in conditions of uncertainty recruitment site for predators and prey, associated to long distance larval dispersal cyc1es. The correlation analysis between radular morphology and diet presented a non significant result, indicating that the radula is a conservative structure, remaining as a useful tool for the systematic assessment of relationship among species, genera, and families
Summary: The gastropods Stramonita haemastoma (Muricidae), Morula nodulosa (Muricidae), Leucozonia trap (Fasciolariidae), and Pisania auritula (Buccinidae), coexist in the intertidal rocky coastline of Brazil, forming a guild that operates sés arrested six or little mobility . The diets of the 4 species were quantitatively analyzed and compared with the abundance of prey in 3 different locations of the Canal of San Sebastian, Brazil. The distribution of predators was also studied. Indices of overlapping Schoener to diet and use of habitat have taken clear that there is a strong sharing of resources between these gastropods in the intertidal region. S. haemastoma and M. nodulosa explored mainly the areas of mediolitoral lower and higher respectively, while L.nassa and P. auritula preferably occupied the fringes of sublitoral. An analysis of diet indicated a marked degree of overlap of niche between the first pair of species, although they eat in different habitats and eat prey of different sizes. The 4 species exhibited broad diets. S. haemastoma consumed mainly molluscs, M. nodulosa explored small barnacles and shellfish, while L.nassa, and P. auritula ingested preferably barnacles large and poliquetos. The muricídeos showed low selectivity of prey exploring the majority of food items according to their availability in the environment. The sharing of habitat is as important as the sharing of food in the structuring of the guild of gastropods predators. Flexibility in the diet is an adaptive strategy under conditions of uncertainty over the site of recruitment of prey and predators, coupled with cycles of larval dispersal over long distances. The analysis of correlation between morphology and diet radular not produced significant results, indicating that the rádula structure is a conservative, remaining as a useful tool for determining systematic relationship between species, genera and families
Abstract: The gastropods Stramonita haemastoma (Muricidae), Morula nodulosa (Muricidae), Leucozonia trap (Fasciolariidae), and Pisania auritula (Buccinidae), coexist in Brazilian intertidal rocky shores, constituting a guild which exploits sessile or slow mobile prey. Diets of the 4 species were quantitatively analyzed and compared with prey abundance in 3 different sites of St. Sebastian Channel, SP, Brazil. Predator distribution was also studied. Schoener 's overlap indices for diet and habitat usage showed that there was strong resource partitioning among those gastropods in the intertidal. S. haemastoma and M. nodulosa mainly exploited the lower and upper midlittoral zones respectively, while L.nassa, and P. auritula preferentially exploited the sublittoral fringe. Diet analysis indicated a marked niche overlap between the first pair of species, although they fed in distinct habitats and ate prey of different sizes. The 4 species exhibited a broad diet. S. haemastoma consumed mainly molluscs, M. nodulosa exploited small barnacles and bivalves, whereas L.nassa, and P. auritula ingested preferentially large barnac1es and polychaetes. The muricids showed low prey selectivity exploiting the majority of prey according to their availability in the environment. Habitat partitioning is as important as food partitioning in structuring this predatory gastropod Guild. Diet flexibility is an adaptive strategy in conditions of uncertainty recruitment site for predators and prey, associated to long distance larval dispersal cyc1es. The correlation analysis between radular morphology and diet presented a non significant result, indicating that the radula is a conservative structure, remaining as a useful tool for the systematic assessment of relationship among species, genera, and families
