scholarly journals PERAN EKOLOGI BULU BABI DALAM KOMUNITAS RUMPUT LAUT DI PERAIRAN PESISIR KEMA KABUPATEN MINAHASA UTARA

2011 ◽  
Vol 7 (1) ◽  
pp. 1
Author(s):  
Ruddy D Moningkey

A study on the functional role of the sea urchin, Salmacis belli, on seagrass bed near the coast of Kema, North Minahasa Regency, was done by analyzing the gut contents, the food preference, and the feeding periodicity. Sea urchins and plants were collected from the seagrass bed by snorkeling along a 100 M transect line with 30 quadrates randomly placed. The feeding periodicity was determined from the gut index in 24 hours with 3 hour intervals.  The results showed that the sea urchin S. belli fed mainly on seagrass Thallasia hemprichii, Enhalus acoroides and Halimeda opuntioa. The feeding periodicity data indicated that the sea urchins actively fed in the day. The grazing capacity of the sea urchin was not affected by their body size.  In high density, sea urchins could potentially cause negative impact on the seagrass bed (i.e., destruction of the meadow).

2020 ◽  
Vol 1 (1) ◽  
pp. 16-21
Author(s):  
La Nane ◽  
Alfi Sahri R Baruadi ◽  
Herinda Mardin

The blue-black urchin has been widely known and utilized as food in the world, including Indonesia because sea urchin gonad can be consumed. However, the utilization of sea urchins in Gorontalo has not been performed. On the other hand, natural resources information is needed as the database for natural resources management in Tomini Bay. The aim of this study is to document the blue-black urchin Echinotrix diadema. This study conducted at Blue Marlin Beach, South Leato, Gorontalo, from November 2019 to December 2020. Sea urchin density was calculated with a 1 m × 1 m transect quadrate that positioned at interval 5 m in distance along 15 m of the transect line at the coral reef ecosystem. In parallel with the measurement of the density, sea urchin test diameter was measured with a Vernier caliper (0.01 mm accuracy), and the water temperature was measured with a thermometer. The results show that the average of sea urchin density is 3 ind. m–2 in November and December and 1 ind.m–2 in January. That density has no significant difference among the month. Moreover, the average size of the sea urchin test diameter is 60 mm in November, 63 mm in December, and 66 mm in January. The seawater temperature is 34 °C in November, 37 °C in December, and 33 °C in January. That results show that sea urchin density in the blue marlin beach is very low.


2015 ◽  
Author(s):  
Simone Farina ◽  
Silvia Oliva ◽  
Ivan Guala ◽  
Rodrigo Silva ◽  
Luigi Piazzi ◽  
...  

In Mediterranean benthic ecosystems of shallow water local-scale predation maintains a main control on both sea urchin population and the ecological structure of macrophyte community. The use of the habitat by local predator guild in dependence on the regional context shapes prey distributions across the environment. On rocky habitat, the sea urchin Paracentrotus lividus is widely known as prey of apex fish predators that indirectly shape the structure of benthic assemblages whereas, in structured Posidonia oceanica, P. lividus can find shelter from predators. In this study, we assessed survival rates of P. lividus in a Marine Protected Area (Sardinia) at the aim to evaluate the role of composition and configuration of landscape on its predation risk. Sites of different landscapes were selected in function of their heterogeneity estimated according to the different proportions and spatial interspersion of four classes of habitats defined on the basis of P. oceanica meadows arrangement: (1) continuous, (2) fragmented and (3) patchy meadows and (4) absence of seagrass (i.e. rocky bottom with macroalgae communities). In order to capture the domain of the ecological process a sampling grain 5x5 meters was used as minimal spatial resolution at which information is assessed. Specifically continuous sampling units in a grid of 7x7 cells yield landscape quadrats of 35 × 35 m and allowed a finer description of the spatial pattern. For each cell we also estimated structural variables of seagrass habitats such as unburied mat, shoot density, canopy height, cover percent, roughness and the natural abundances of prey and predators. After placing the tagged sea urchins, we daily observed the survival rates for twenty days. Predation risk was significantly higher in continuous and fragmented seagrass habitats and predator marks were typically produced by gastropod’s attacks. Landscape indices are used to correlate the amount of available habitat for gastropods movements with sea urchin’s predation risk. Interestingly, estimated predation rate also was negatively correlated with natural sea urchins density across grid cells. Results suggest that, although fishes are considered among the most important pressures on sea urchin population, especially in effective MPAs, bottom predators’ control can be relevant in structurally complex environment such as seagrasses.


2015 ◽  
Author(s):  
Simone Farina ◽  
Silvia Oliva ◽  
Ivan Guala ◽  
Rodrigo Silva ◽  
Luigi Piazzi ◽  
...  

In Mediterranean benthic ecosystems of shallow water local-scale predation maintains a main control on both sea urchin population and the ecological structure of macrophyte community. The use of the habitat by local predator guild in dependence on the regional context shapes prey distributions across the environment. On rocky habitat, the sea urchin Paracentrotus lividus is widely known as prey of apex fish predators that indirectly shape the structure of benthic assemblages whereas, in structured Posidonia oceanica, P. lividus can find shelter from predators. In this study, we assessed survival rates of P. lividus in a Marine Protected Area (Sardinia) at the aim to evaluate the role of composition and configuration of landscape on its predation risk. Sites of different landscapes were selected in function of their heterogeneity estimated according to the different proportions and spatial interspersion of four classes of habitats defined on the basis of P. oceanica meadows arrangement: (1) continuous, (2) fragmented and (3) patchy meadows and (4) absence of seagrass (i.e. rocky bottom with macroalgae communities). In order to capture the domain of the ecological process a sampling grain 5x5 meters was used as minimal spatial resolution at which information is assessed. Specifically continuous sampling units in a grid of 7x7 cells yield landscape quadrats of 35 × 35 m and allowed a finer description of the spatial pattern. For each cell we also estimated structural variables of seagrass habitats such as unburied mat, shoot density, canopy height, cover percent, roughness and the natural abundances of prey and predators. After placing the tagged sea urchins, we daily observed the survival rates for twenty days. Predation risk was significantly higher in continuous and fragmented seagrass habitats and predator marks were typically produced by gastropod’s attacks. Landscape indices are used to correlate the amount of available habitat for gastropods movements with sea urchin’s predation risk. Interestingly, estimated predation rate also was negatively correlated with natural sea urchins density across grid cells. Results suggest that, although fishes are considered among the most important pressures on sea urchin population, especially in effective MPAs, bottom predators’ control can be relevant in structurally complex environment such as seagrasses.


Zoosymposia ◽  
2012 ◽  
Vol 7 (1) ◽  
pp. 247-254 ◽  
Author(s):  
SILVIA MERCURIO ◽  
MICHELA SUGNI ◽  
DENISE FERNANDES ◽  
CINTA PORTE ◽  
MARIA DANIELA CANDIA CARNEVALI

Despite the extensive use of sea urchins in embryology, the hormonal mechanisms regulating echinoid reproductive pro­cesses are scarcely known. This research is focused on the role of estradiol (E2), whose presence and seasonal variations in different echinoderm tissues have been previously reported. Three different concentrations of E2 were administered (via peristomial injection, 2/week) to adult specimens of the sea urchin Paracentrotus lividus for 2 and 12 weeks. The lowest concentration was close to physiological values, previously measured in field specimens. Despite the increase of circulating E2 in the coelomic fluids, neither short- nor long-term hormonal treatment induced marked variations in the considered reproductive parameters. The Gonad Index appeared to be more influenced by the feed intake than by E2. Similarly, the maturation stage of the gonads was not markedly affected by E2 injection, although some sex-specific dif­ferences could be observed: treated females never reached the maximum maturation stage compared to controls, although this was observed in males injected with the lowest E2 concentration. Although further research is needed to confirm our observations, according to the present study E2 does not markedly influence echinoid reproduction and, particularly, it does not promote female maturation, as reported for vertebrates and suggested for asteroid echinoderms.


2018 ◽  
Vol 21 (1) ◽  
pp. 41
Author(s):  
Retno Hartati ◽  
Endika Meirawati ◽  
Sri Redjeki ◽  
Ita Riniatsih ◽  
Robertus Triaji Mahendrajaya

Abstract Types of Star Fish and Sea Urchins (Asteroidea, Echinoidea: Echinodermata) In Cilik Island, Karimunjawa WatersEchinoderms are fundamentally good indicators of health and status of coralline communities in marine waters.  Substrat of  sandy, rububle and coral reefs are good habitat for Asteroidea dan Echinoidea.  This study aim to identify sea star (Asteroidea) and sea urchin (Echinoidea) species from Pulau Cilik waters of Karimunjawa Islands. Asteroidea and Echinoidea observed using the line transect method used, ie subjects within the same distance between the transect and the transect square with observations of 2.5 m on the right and left of transect line line. Morphology, habitat type (substrate & depth) and total number of sea stars and sea urchins at each station were determined. The results showed that Pulau Cilik has six species of Asteroidea (Sea star), ie Linckia laevigata, L. multifora, Neoferdifla ocellata (Family Ophidiasteridae), Luidia alternate (Luidiidae Family), Culcita novaeguineae (Family Oreasteridae) and Acanthaster planci which belongs to Family Acanthasteridae. There were 4 species of Echinoidea Sea urchin) found, i.e. Diadema setosum, D. antillarum, D. savignyi and Echinothrix calamaris, which all were family members of Diadematidae Keywords: Ophidiasteridae, Luidiidae, Oreasteridae, Acanthasteridae, Diadematidae AbstrakEchinodermata pada dasarnya merupakan indikator kesehatan dan status dari terumbu karang di laut. Dasar perairan yang landai dengan substrat pasir, terumbu karang dan pecahan karang yang merupakan habitat bagi hewan jenis Asteroidea dan Echinoidea. Penelitian ini bertujuan untuk mengidentifikasi henis-jenis bitang laut dan bulu babi dari perairan Pulau Cilik, Kepulauan Karimunjawa. Pengamatan Asteroidea dan Echinoidea menggunakan metoda line transect yang dimodifikasi, yaitu mengamati subjek dalam jarak yang sama sepanjang garis transect dan kuadrat transect dengan pengamatan 2,5 m di sebelah kanan dan kiri garis line transect. Morfologi, tipe habitat (substrat & kedalaman) dan jumlah total bintang laut dan bulu babi di tiap stasiun dicatat selanjutnya sampel diidentifikasi berdasarkan ciri morfologi tersebut. Hasil penelitian menunjukkan bahwa di perairan Pulau Cilik ditemukan enam spesies Asteroidea (Bintang Laut), yaitu Linckia laevigata, L. multifora, Neoferdifla ocellata (Famili Ophidiasteridae), Luidia alternate (Famili Luidiidae), Culcita novaeguineae (Famili Oreasteridae) dan Acanthaster planci yang termasuk dalam Famili Acanthasteridae. Species Echinoidea (Bulu Babi) ditemukan 4 spesies  Diadema setosum, D. antillarum, D. savignyi dan Echinothrix calamaris  semua anggota famili Diadematidae.Kata kunci : Ophidiasteridae, Luidiidae, Oreasteridae, Acanthasteridae, Diadematidae


2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Kit Yu Karen Chan ◽  
Chun Sang Daniel Tong

Abstract Coastal organisms reside in highly dynamic habitats. Global climate change is expected to alter not only the mean of the physical conditions experienced but also the frequencies and/or the magnitude of fluctuations of environmental factors. Understanding responses in an ecologically relevant context is essential for formulating management strategies. In particular, there are increasing suggestions that exposure to fluctuations could alleviate the impact of climate change-related stressors by selecting for plasticity that may help acclimatization to future conditions. However, it remains unclear whether the presence of fluctuations alone is sufficient to confer such effects or whether the pattern of the fluctuations matters. Therefore, we investigated the role of frequency and initial conditions of the fluctuations on performance by exposing larval sea urchin Heliocidaris crassispina to either constant or fluctuating pH. Reduced pH alone (pH 7.3 vs 8.0) did not affect larval mortality but reduced the growth of larval arms in the static pH treatments. Changes in morphology could affect the swimming mechanics for these small organisms, and geometric morphometric analysis further suggested an overall shape change such that acidified larvae had more U-shaped bodies and shorter arms, which would help maintain stability in moving water. The relative negative impact of lower pH, computed as log response ratio, on larval arm development was smaller when larvae were exposed to pH fluctuations, especially when the change was less frequent (48- vs 24-h cycle). Furthermore, larvae experiencing an initial pH drop, i.e. those where the cycle started at pH 8.0, were more negatively impacted compared with those kept at an initial pH of 7.3 before the cycling started. Our observations suggest that larval responses to climate change stress could not be easily predicted from mean conditions. Instead, to better predict organismal performance in the future ocean, monitoring and investigation of the role of real-time environmental fluctuations along the dispersive pathway is key.


2021 ◽  
Vol 4 (2) ◽  
pp. 112-116
Author(s):  
Nainul Adni ◽  
Aras Mulyadi ◽  
Thamrin Thamrin

Poncan Godang Island is included in the appropriate category based on the suitability of land for the Sibolga tourist area, with the presence of tourism activities that can also affect the amount of biodiversity in it. Considering the importance of coral reefs for biodiversity and sea urchins which also have a role in coral reef ecosystems, it is necessary to conduct research on the condition of sea urchins population and the percentage of coral reefs on Poncan Godang Island. Sea urchin and coral reef data were collected using the Line Intercept Transect (LIT) method by monitoring directly on the transect line along 50 meters. The results obtained indicate that the population of sea urchins in the waters of Poncan Godang Island, North Sumatra can be described, that sea urchins do not affect the coral reef ecosystem because at stations 1 and 5 there is no sea urchin and the percentage of coral cover is classified as bad, but at station 3 there are 32 individuals with coral reef cover conditions, while at stations with The percentage of good coral cover is that at station 4 there are only 25 individuals, as well as at station 2 where the percentage of coral cover is higher than station 3 and there are no sea urchins


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