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The ecology of the grazing urchin Echinometra mathaei at Ningaloo Marine Park
Full text linkSea urchins can have a significant influence upon the ecological structure of coral reefs through both bioerosion of substrata and by affecting competition for space. Loss of reef structure can limit space for algal and coral recruitment which further alters the balance between reef growth and reef destruction. Urchins are important grazers in many marine systems and can cause major ecosystem changes when their numbers reach high levels (generally after a decline in the numbers of their fish predators). However, the relative importance of the role of urchins in influencing the composition and structure of coral reef habitats has rarely been explored.
This thesis investigated the habitat preferences, distribution, grazing, bioerosion, and behaviour of the grazing urchin Echinometra mathaei at Ningaloo Marine Park (NMP), Western Australia. Coral reef habitats of the NMP were characterised using field surveys and validations of broad-scale hyper-spectral benthic habitat maps; the effects of habitat type and different closure regimes (e.g. Sanctuary zones) on urchin distribution and abundance were then examined and compared. This thesis represents the first study to quantify the grazing and consequent bioerosion rates of E. mathaei at Ningaloo Reef and the first to study their animistic behaviour and diurnal movement patterns.
Data were collected from over 100 sites within the Marine Park, focussing on near shore, lagoonal and back reef areas within Sanctuary zones and adjacent Recreation zones. Data analyses indicated that the distribution of urchins was variable and appears not to be affected by the management zones of the park (i.e. no significant evidence has been found of indirect effects from fishing of known urchin predators).
However, habitat type had a major influence on urchin distribution; urchin abundances were higher on nearshore intertidal and sub-tidal reef platforms, lagoonal patch reefs and shallow backreef platforms than in other habitats. Data analysis showed strong positive correlations between urchin densities and habitats that contained turf algae, and a combination of limestone pavement and turf algae.
Grazing and bioerosion studies demonstrated that although E. mathaei grazing plays an important ecological role, concomitant bioerosion may play a more central role in influencing the structure of coral reef communities than grazing at the NMP. Urchin, morphometrics and gut content analyses from different habitats in four regions of the NMP indicated higher mean urchin densities, size and subsequent bioerosion rates in southern regions than in the north of the park. Bioerosion rates from Ningaloo Reef (1.0 - 4.5 kg m-2 year-1 of CaCO3) were found to be comparable to degraded (overfished) reef systems in other parts of the world, but without accurate estimates of CaCO3 accretion rates it is difficult to determine the degree to which bioerosion is affecting reef growth at the NMP or if it is any more or less significant than in other parts of the world. Results from this study suggest that habitats at Ningaloo with high E. mathaei densities are more likely to be niche habitats that co-exist with other coral reef habitats as part of a healthy ecosystem.
Video footage of diurnal movement revealed that E. mathaei did not leave their burrows to graze but were systematically “gardening’ turf within longitudinal burrows at night and sheltering from predators during the day. Observations of animistic behaviour experiments showed that they would also defend their burrows when threatened by intruding conspecifics but the majority of interactions would result in urchins coexisting in the same longitudinal burrow. This type of territorial grazing behaviour within long, tube-like burrows has been documented for other urchin species (e.g. the northern Atlantic echinoid, E. lucunter) but never for E. mathaei. Defence of (and sharing of) longitudinal burrows may also be associated with other predation avoidance behaviour
KELIMPAHAN DAN STRUKTUR POPULASI Echinometra mathaei (CLASS ECHINOIDEA) DI KAWASAN INTERTIDAL PANTAI MANDALIKA LOMBOK TENGAH SEBAGAI SUMBER BELAJAR BIOLOGI
Full text linkBulu babi Echinometra mathaei adalah salah satu biota laut dari Filum Echinodermataàyang banyak terdapat di kawasan intertidal Pantai Mandalika, Kecamatan Pujut, KabupatenàLombok Tengah. Tujuan penelitian ini adalah mendeskripsikan kelimpahan dan struktur populasiàserta mengeksplorasi perbedaan kelimpahan E. mathaei antar jenis substrat, perbedaan ukuranàdiameter antar zona, dan hubungan kelimpahan E. mathaei dengan tutupan makroalgae. Dataàkelimpahan dikoleksi dengan metode transek kuadrat, dengan ukuran kuadrat 5x1 m2. Data ukuranàdiameter diambil dengan menggunakan kaliper. Hasil penellitian menunjukkan rata-ratañSDàkelimpahan E. mathaei adalah 39,75ñ47,78 individu per kuadrat atau 795 individu per are (100àm2). Kelimpahan populasi E. mathaei berbeda di ketiga transek. Perbedaan kelimpahan populasi E.àmathaei juga ditemukan antara substrat terumbu karang dan batuan vulkanik. Ada hubunganàkorelasi negatif antara tutupan makroalgae dengan kelimpahan E. mathaei. Struktur populasi diàPantai Mandalika menunjukkan bahwa proporsi populasi E. mathaei yang mampu reproduksiàsekitar 84,87%.Kata kunci: Populasi, Echinometra mathaei, di kawasan Intertidal, Pantai Mandalika
Impact Test Size and Type of Echinometra mathaei as Agent of Bioerosion on Reef Flat (Pengaruh Ukuran dan Tipe Echinometra mathaei pada Bioerosi Karang)
No full textBioerosi adalah aktivitas berbagai organisme yang menyebabkan terjadinya erosi dan kerusakan misalnya pada kalsium karbonat karang. Aktivitas ini merupakan faktor utama yang mempengaruhi morfologi terumbu karang. Bioerosi dipengaruhi oleh tiga variabel yakni jenis spesies, ukuran dan kelimpahan spesies tersebut. Tujuh puluh lima persen dari bioerosi disebabkan oleh landak laut. Perbedaan pada ukuran dan jenis landak laut memberikan dampak signifikan terhadap daerah yang terjadi bioerosi. Penelitian ini bertujuan untuk menguji pengaruh ukuran dan jenis landak laut E. mathaei (tipe A dan B) pada komposisi CaCO3 dalam isi usus dan tinja organisme tersebut sebagai agen bioersi. Landak laut yang digunakan diperoleh dari ekosistem karang di pantai Minatogawa, Okinawa-Jepang. Masing-masing tipe landak laut dibedakan berdasarkan ukuran ≥30 mm dan <30mm. Penelitian dilakukan dengan tiga ulangan. Pemeliharaan ini dilakukan di laboratorium dengan analisis komposisi CaCO3 pada tinja dan konten usus. Hasil penelitian membuktikan bahwa komposisi CaCO3 disebabkan karena aktivitas bioerosi harian dari E. mathaei. Landak laut dengan ukuran diameter ≥30 mm terbukti lebih aktif dibandingkan dengan diameter <30mm. Disamping itu landak laut tipe B lebih aktif dibandingkan tipe A dengan ukuran yang sama. Persentase CaCO3 dalam usus selama pemeliharaan di laboratorium adalah 73% dan sisa 27% berupa bahan organik dan anorganik. Bierosion harian E. mathaei tipe A ≥ 30 mm 166,70 mg.hari-1, tipe A <30 mm 77.78 mg.hari-1, tipe B ≥ 30 mm 126,30 mg.hari-1, tipe B <30 mm 116,17 mg.hari-1. Tingkat bioerosion harian E. mathaei dipengaruhi oleh jenis, spesies, kecepatan menggiling, dan ukuran landak laut.
Kata kunci: ukuran; Echinometra mathaei; bioerosi; karang
Bioerosion is an activity of various organisms such as erosion and destruction of coral calcium carbonate and become a major factor influencing coral reefs morphology. Bioerosion is influenced by three variables: type of species, size of species and abundance. Seventyfive percent of bioerosion caused by sea urchin. Differences on size and type of sea urchin gave a significant impact to the bioerosion area. This study aimed to examine the influence of the size and the type of sea urchin E. mathaei (type A and type B) on the composition of CaCO3 in the gut content and feces as bioersion agent on the reef flat in Minatogawa Coast, Okinawa-Japan. The organisms used were E. mathaei type A and type B with each type distinguished by size ≥ 30 mm and < 30 mm with three replications. The maintenance was carried out at laboratory for 3 days by observing analysis of the composition of CaCO3 on feces and gut content. It indicates that the composition of CaCO3 as daily bioerosion was caused by E. mathaei. The results showed E. mathaei with diameter ≥ 30 mm was more active than those with diameter of < 30mm and type B was more active than type A in each of the same size. Percentage of CaCO3 in the gut during maintenance in the laboratory was 73% and the other 27% consist of organic and inorganic materials. Daily bierosion E. mathaei type A ≥ 30 mm 166.70 mg.day-1 , type A < 30 mm 77.78 mg.day-1 , type B ≥ 30 mm 126.30 mg.day-1 , type B < 30 mm 116.17 mg.day-1. Daily bioerosion rate E. mathaei was influenced by the type, species, speed of grind, and the size of the sea urchin.
Keywords: size; Echinometra mathaei; bioerosion; reef fla
Aktivitas Analgesik Ekstrak Etanol Bulu Babi (ECHINOMETRA MATHAEI) Pada Mencit Putih Jantan
Full text linkSea urchin (Echinometra mathaei) is a potential marine resourches that had not been explored widely. It has flavonoid, triterpenoid, alkaloid, saponin compound with high antioxidant activity. Antioxidant activity and flavonoid compound were potentially correlated with analgesic activity. This study aimed to examine e the potential of Echinometra mathaei as an analgesic in white male mice that were induced by acetic acid to produce peripheral pain in vivo (streatching in mice) with writhing test method. The amount of stretching was observed for 1 hour after administration of ethanol extract of Echinometra mathaei orally. Balb/c white mice which devided into 6 groups randomlly, as negative control group, a group that induced acetic acid 1%, Asetosal group with dose of 65 mg/kgBW, and Echinometra Mathaei groups with the dose of 100 mg/kgBW, 200 mg/kgBW, and 400 mg/kgBW. The results of this study showed that all dosage of Echinometra mathaei decrease the peripheral compared to negative control (P,0.05). The percentage inhibition of pain at 200 mg/kgBW (72.59%) was the highest among other doses was significant different from asetosal group (52.53%). This research concluded that Echinometra mathaei has the analgesic activity to inhibit peripheral pain .
Keywords: Echinometra mathaei, ethanol extract, analgesic, mice, writhing tes
Experimental hybridization between two recently diverged species of tropical sea urchins, echinometra mathaei and echinometra oblonga
No full textTwo species of tropical sea urchins, Echinometra mathaei and Echinometra oblonga, occur abundantly on Okinawan intertidal reefs; E. mathaei is found mainly on inshore reef flats while E. oblonga burrows in the offshore reef margins. The two species spawn during the same season, and hybrid embryos can be formed in the laboratory. We confirmed earlier experiments showing that fertilization rates are high between eggs of E. oblonga and sperm of E. mathaei, but significantly lower than those in homogametic crosses, whereas few eggs of E. mathaei are fertilized by sperm of E. oblonga, even at very high sperm concentrations. If they spawn together in the field, most or all ova of E. oblonga would be fertilized by conspecific sperm before encountering sperm of E. mathaei on the reef flat, so hybridization is partially minimized by habitat separation. However, many viable sperm of E. oblonga would still be available to fertilize ova of E. mathaei. Species-specific differences in sperm chemotaxis or gamete compatibility may provide prezygotic barriers that also would prevent hybridization, especially between ova of E. mathaei and sperm of E. oblonga. We found that homogametic crosses reach peak fertilization levels much sooner than heterogametic crosses, even between ova of E. oblonga and sperm of E. mathaei, indicating the presence of prezygotic barriers to hybridization in the gametes. Nevertheless, laboratory crosses between E. mathaei and E. oblonga in both directions produced viable hybrids that developed through larval and juvenile stages to sexually mature adults. Phenotypic color pattern of hybrids tended to be maternal while other characteristics were intermediate (test size, weight, spine length, growth, tubefoot and gonad spicule morphology, pedicellaria valve length, gamete size). Adult F1 hybrids from both combinations were completely fertile and exhibited high fertilization rates in backcrosses. On the other hand, intensive field surveys failed to find hybrids, showing the rarity or absence of natural hybridization. These results mirror those found with hybridization studies on other species of Echinometra on Okinawa. They further support the conclusion that prezygotic isolating mechanisms such as habitat segregation as well as species-specific sperm chemotaxis and/or gamete compatibility have a role in maintaining the genetic integrity of these species. © 2004 Taylor & Francis Group, LLC
Determination of developmental stages of embryo in the Sea Urchin, Echinometra mathaei
No full textSea Urchin is one of the most useful tools in developmental biology studies because this organism has the simplest kind of developmental stages. We aimed to determine developmental stages and timetable of Echinometra mathaei embryo (the species of Persian Gulf). The spawning of E. mathaei was induced by 0.5M KCl injection (1ml) into the coelomic cavity. After fertilization, embryos were placed in beakers and were incubated at 29◦C and a salinity of 39 ppt until embryos reached the pluteus stage. The developmental stages of embryos and the timing of each stage including cleavage, morulae, blastula, gastrula, prism and pluteus larvae were studied under the microscope. Our results showed that after 30 hours from fertilization time, the embryos developed to pluteus larvae. E. mathaei had the shorter development time in comparison to the other Sea Urchin species. Therefore, it may be appropriate as a model organism in biological researches.Publishe
New Record of a Sea Urchin Echinometra mathaei (Echinoidea: Camarodonta: Echinometridae) from Jeju Island, Korea and Its Molecular Analysis
No full textEchinoids were collected at depths of 5-10 m in Munseom, Jeju Island by SCUBA diving on November 23, 2008 and September 15, 2009. Two specimens were identified as Echinometra mathaei (Blainville, 1825) based on morphological characteristics and molecular analyses of mitochondrial cytochrome c oxidase subunit I partial sequences. Echinometra mathaei collected from Korea was redescribed with photographs and was compared with other species from GenBank based on molecular data. Phylogenetic analyses showed that no significant differences were between base sequences of E. mathaei from Korea and that from GenBank. To date, 13 echinoids including this species have been reported from Jeju Island, and 32 echinoids have been recorded in Korea
Determination of developmental stages of embryo in the sea urchin, Echinometra mathaei
Full text linkSea Urchin is one of the most useful tools in developmental biology studies because this organism has the simplest kind of developmental stages. We aimed to determine developmental stages and timetable of Echinometra mathaei embryo (the species of Persian Gulf). The spawning of E. mathaei was induced by 0.5M KCl injection (1ml) into the coelomic cavity. After fertilization, embryos were placed in beakers and were incubated at 29°C and a salinity of 39 ppt until embryos reached the pluteus stage. The developmental stages of embryos and the timing of each stage including cleavage, morulae, blastula, gastrula, prism and pluteus larvae were studied under the microscope. Our results showed that after 30 hours from fertilization time, the embryos developed to pluteus larvae. E. mathaei had the shorter development time in comparison to the other Sea Urchin species. Therefore, it may be appropriate as a model organism in biological researches
Standarisasi Ekstrak Etanol 96% Bulu Babi Echinometra Mathaei Dari Perairan Bangkalan
Full text linkEchinometra mathaei sea urchins are known to contain chemical compounds that can be used to overcome health problems, one of which has antioxidant activity. Some previous studies have explained the benefits of sea urchins but to ensure the quality assurance of sea urchins extracts, efforts should be made to determine the quality standards of sea urchins extract. This study aims to standardize specific parameters and non-specific parameters on Echinometra mathaei sea urchins extract to ensure the quality of 96% ethanol extract. Samples were obtained from Rongkang Beach, Kwanyar District, Bangkalan District, Madura which were then extracted using maceration method with 96% ethanol solvent. The results of the study for specific parameters showed that organoleptically and macroscopically the extracts were thick, blackish brown in color and characteristic of sea urchins; levels of dissolved compounds in ethanol of 78.37%; levels of dissolved compounds in water of 93.09%; and chemical content tests showed that the extract contained steroid compounds, tannins, flavonoids, saponins, alkaloids and terpenoids. Determination of non-specific parameters showed that Echinometra mathaei sea urchin extract had a drying shrinkage of 3.03%; specific gravity of 0.8411 g/mL; water content of 5.32%; Pb heavy metal contamination was 7.28 mg/kg, Cd was <0.0024 mg/kg, Hg was <0.0002 mg / kg, Mg was 347.83 mg / kg; microbial contamination of <10 colonies / mL; and yeast mold contamination of <10 colonies/mL. The conclusion is Echinometra mathaei sea urchin extract has the potential to be developed into a medicinal preparation. Key word: Echinometra mathaei, Specific standardize parameters, non-specific standardize parameters, Extract thanol 96%
Mathaei Parisiensis, monachi Sancti Albani, historia Anglorum..., par sir Frederic Madden.
No full textMathaei Parisiensis, monachi Sancti Albani, historia Anglorum..., par sir Frederic Madden.. In: Bibliothèque de l'école des chartes. 1870, tome 31. pp. 566-567
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