Iron, Manganese, and Nickel in Skeletons and Food of the Sea Urchins Tripneustes Esculentus and Echinometra Lucunter1

Abstract

Levels of the trace elements Fe, Ni, and Mn were determined in the skeletons of the sea urchins Tripneustes esculentus (Leske) and Echinometra lucunter (L.) and compared between animals of the same species collected at Punta Higuero and at La Parguera, Puerto Rico. Differences between species were also compared. Levels of Mn and Ni were higher in E. lucunter than in T. esculentus, reflecting a species difference. Levels of Fe in T. esculentus from Punta Higuero were significantly higher than in those from La Parguera. The trace element contents of Padina gymnospora, the principal forage plant of T. esculentus at Punta Higuero and of Thalassia testudinum, the principal forage plant of T. esculentus at La Parguera were compared. P. gymnospora contained significantly more Fe than T. testudinum, showing a relationship between the amount of Fe in the skeletons of T. esculentus and their food. The higher levels of Mn and Ni in P. gymnospora were not reflected in the urchin skeletons. Relationships between food, temperature, and salinity are discussed in relation to the trace element content of the urchins.

Effects of seawater chemistry (Mg2+/Ca2+ ratio) and diet on the skeletal Mg/Ca ratio in the common sea urchin Paracentrotus lividus

“…Overall these results strongly suggest that seawater may not be the only source of ions in echinoderm biomineralization, consistent with previous hypothesis by Asnaghi et al (2014). Notably, in the case of other ions, a clear relationship between the contents of Fe 2+ in echinoderm skeletons and consumed algae was found, suggesting that skeletal Fe derives from food (e.g., Stevenson and Ufret, 1966).…”

Effect of artificial destratification on iron, manganese, and zinc in the water, sediments, and two species of benthic macroinvertebrates in an Oklahoma lake

“…The average concentrations were 858 and 2 941 µg g -1 for Chaoborus punctipennis and Chironomus riparius, respectively, while the concentration factors averaged 1 021 and 5 111 . These concentrations are within the ranges of those reported for other invertebrates (Stevenson & Ufret 1966 ;Cross et al 1970 ;Windom & Smith 1972) . The considerably great concentration in C. riparius was probably related to the greater demands of iron by this species because of the presence of iron containing hemoglobin .…”

Metal concentrations in certain coastal organisms from Beirut

“…This may not be unusual because both are often in close contact with the sea bottom and in Ras Beirut, iron is very high in sediment (Shiber, 1980) . The fact that sediment has been found in the intestines of sea urchins (Stevenson and Ufret, 1966) might suggest that some metals in sea urchins could partially be derived from the sediment, as might be the case with certain metals in polychaetes (Bryan & Hummerstone, 1971) and shell fish (GESAMP, 1976) . However, relationships between metal concentrations in Mediterranean sediment and various biota have yet to be investigated .…”

“…It has been shown that sea urchins can thrive in and around areas of sewage input and absorb dissolved organic matter, i .e ., amino acids released in sewage discharges (North, In: Marx, 1971, pp . 19-20), and heavy metals (Stevenson & Ufret, 1966) through their integument . Regis (1979) recently reported that Arbacia lixula is capable of absorbing dissolved materials from its surrounding medium .…”