scholarly journals Density of the blue-black urchin Echinotrix diadema (Linnaeus, 1758) in Tomini Bay, Indonesia

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.

2020 ◽  
Vol 25 (2) ◽  
pp. 53-56
Author(s):  
La Nane ◽  
Arfiani Rizki Paramata

Sea urchin Tripneustes gratilla is one of an economically important fisheries resource product for localities at Wakatobi archipelago. High demands for sea urchin gonad have intensified high fishing activity. The hypothesis of this study is that sea urchins in Wakatobi have been overfished. To answer that hypothesis, the density and its test diameter size were measured at two different sites. Those two sites are Pulau Tomia (resident area) and Pulau Sawa (nonresident area and very distant from the localities). The results show that sea urchin density and its test diameter are significantly different.  The densities (mean±SE) T. gratilla at Pulau Sawa and Pulau Tomia were 10±0.6 (ind.m-2) and 2.7±0.9 ind.m-2, respectively. Moreover, the test diameter at Pulau Sawa and Pulau Tomia were 69.7±2.1 mm and 58.5±1.7 mm (mean±SE), respectively. These results have shown that overfishing has occurred. Therefore, sea urchin with test diameter 66–75 mm, 76–85 mm, and 86–95 mm have disappeared at Pulau Tomia. The Conclusion reveals that fishing of sea urchin Tripneustes gratilla at Pulau Tomia has been overfished.


2019 ◽  
Author(s):  
La Nane

AbstractSea urchin Tripneustes gratilla is one of an economic important fisheries resources product for localities at Wakatobi archipelago. High demands for sea urchin gonad have intensified high fishing activity. We hypothesize that sea urchins at Wakatobi have overfished. To answer that hypothesizes; we measure the density and its test diameter size at two different sites. They are Pulau Tomia (inhabited area) and Pulau Sawa (uninhabited area and very distant from the localities). The results show that sea urchin density and its test diameter is significantly different. The densities (mean ± SE) Tripneustes gratilla at Pulau Sawa and Pulau Tomia are 10 ± 0.6 (ind./m2) and 2.7 ± 0.9 ind./m2, respectively. Moreover, the test diameter at Pulau Sawa and Pulau Tomia are 69.7 ± 2.1 mm (mean ± SE), and 58.5 ± 1.7 mm (mean ± SE), respectively. These results have indeed shown that overfishing has occurred. Therefore, sea urchin with test diameter 66–75 mm, 76–85 mm, and 86–95 mm have disappeared at Pulau Tomia. Our conclusion reveals that fishing of sea urchin Tripneustes gratilla at Pulau Tomia has overfished.


2017 ◽  
Vol 188 (1) ◽  
pp. 140-154
Author(s):  
Maria O. Chalienko ◽  
Marianna V. Kalinina

Population of pale sea urchin Strongylocentrotus pallidus in Peter the Great Bay is investigated. The samples for its size structure and distribution were collected at the depth from 5 to 700 m in July 2013, 2014 and in April 2015 and the samples for the state of gonads, intestines and age structure - at the depths of 41, 69, 280, 346, and 670 m in early April 2015. The size structure at different depths is significantly different: the large individuals with average size of 70.0 mm (portion of commercial ones 98 %) occupy mainly the middle shelf area with the depths of 55-100 m, deeper at the depths of 100-200 m the portion of commercial urchins is lower (67 % in 2014 and 92 % in 2015), and the continental slope (depth > 200 m) is occupied by mainly (77-96 %) non-commercial individuals with average size of 35.5 mm. Age of sea urchins was determined by the growth zones on plates of their shells processed by Jensen method and varied from 3 to 12 years. The growth rate of sea urchins from the shelf areas was approximately in 1.5 times higher as compared with those from the continental slope, primarily due to different conditions of feeding. The gonads cellular composition was defined for the samples of 50 cells per female. The cells were differentiated in the categories of oocytes proliferation, oocytes differentiation, and mature eggs, and the gonad maturity stage was determined by domination of these categories, taking into accounts the S. pallidus reproductive cycle. In spring, the sea urchins from the shelf areas (depths of 41 and 69 m) were generally more mature as compared with those from the continental slope (depths of 280 and 346 m). However, correlation between the gonadal index and depth of habitat was not significant because the mature females were sampled in any depth. Composition of intestinal content and food components were determined visually, looking the bolus under binocular microscope. The sea urchins intestines were mostly filled with detritus at the depth of 41 m, sponges (Suberites sp.) at the depth of 69 m (70 % of cases), and unedible substances as silt and sand at the depth of 280, 346 and 670 m, minor fractions were the algal litter, remains of crustaceans, and detritus.


2021 ◽  
Author(s):  
◽  
Philip James

<p>The roe of sea urchins (Echinodermata: echinoidea) is a prized seafood in a number of countries around the world, including New  Zealand. Increasing fishing pressure on world sea urchin stocks has failed to meet demand. This has led to increasing worldwide interest in roe enhancement of sea urchins. In New Zealand kina (Evechinus chloroticus) have also been heavily fished. However, there are large numbers of poor quality (low gonad index or GI) kina found in kina barrens which are uneconomic to harvest due to low returns. The primary aim of this research was to identify the key holding and environmental conditions for roe enhancement of E. chloroticus to assist in the development of a roe enhancement industry for E. chloroticus to utilise this resource. A series of experiments testing the optimal holding conditions for E. chloroticus in both land- and sea-based holding systems showed that culture depth (3 and 6 m) and removal of the urchins from the water three times per week had no significant effect on gonad growth or urchin mortality. However, exposing E. chloroticus to increased water movement resulted in significantly greater gonad growth in 12 weeks. Increasing water movement is believed to increase the available dissolved oxygen and facilitate the removal of metabolites from around the urchins. Gonad development was not negatively impacted at the maximum stock density tested (6 kg urchin m-2 of internal surface area) and this density is recommended. There are significantly lower running and maintenance costs when E. chloroticus are enhanced in sea-based compared to land-based systems but a full economic analysis is required to assess which is likely to be the more economical option for future roe enhancement. A period of 9 to 12 weeks appears to be the optimal period for roe enhancement in terms of the maximum increase in GI in the shortest time period. Repeated experiments over a 12 month period showed that food availability was the primary driver of roe enhancement (i.e. increase in gonad size) in E. chloroticus. This is followed by seawater temperature, which drives much of the seasonal variation in the gonad size that is observed in wild urchins. This is likely to be due to increased food consumption at higher temperatures. The reproductive stage of E. chloroticus had very little effect on the increase in gonad size of enhanced urchins other than in autumn when gonad growth was slightly lower than in all other seasons. Optimal gonad growth in this study was obtained at 18oC, which was the highest temperature tested. Higher temperatures also resulted in an increase in the rate of progress of the gametogenic cycle of E. chloroticus whilst lower temperatures tended to slow the rate of progress. The effects of temperature on gonad growth (i.e. increased growth at higher temperatures) were consistent across seasons. Photoperiod had minimal effect on gonad growth and the reproductive stage of the urchins over periods of 12 weeks. Photoperiod may still affect gametogenesis of E. chloroticus over longer periods. Low GI kina appear to be capable of significantly larger increases in GI in 10-week periods than high GI kina, as a result of their higher tolerance to stress. This thesis has contributed to improving the technical and economic feasibility of roe enhancement of kina (E. chloroticus) in New Zealand.</p>


2010 ◽  
Vol 6 (2) ◽  
pp. 73
Author(s):  
Ruddy D Moningkey

Sea urchins of different colors were collected 50 individuals each and measured their morphological characters. The data were then transformed to natural logarithm and analyzed using regression. The comparison of the regression line intercept for the shell diameter-height relationship did not show any difference, but there was a significant difference for the shell lenght-heigth relationship. The comparison between different colors exhibited variations in the shell morphology of each sea urchin population. The growth of black spined-sea urchin (Echinometra mathaei), was negative allometric; the fact that they were mostly found in the narrow crevices might have influenced their growth.


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


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).


2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
Archana Ayyagari ◽  
Ramesh Babu Kondamudi

The present study reports a new association between the sea urchinStomopneustes variolaris(Lamarck, 1816) and the polychaeteLumbrineris latreilli(Audouin & Milne Edwards, 1834) based on the specimens collected intertidally at Bay of Bengal (Visakhapatnam, east coast of India). Out of 60 sea urchins collected, 10 (16.67%) were associated with the polychaete. The prevalence increased with the increasing sea urchin test diameter. All polychaetes were exclusively found between the spines, in the aboral region of the host. This association protects the polychaete from the predators during displacement from its natural habitat.


2021 ◽  
Author(s):  
◽  
Philip James

<p>The roe of sea urchins (Echinodermata: echinoidea) is a prized seafood in a number of countries around the world, including New  Zealand. Increasing fishing pressure on world sea urchin stocks has failed to meet demand. This has led to increasing worldwide interest in roe enhancement of sea urchins. In New Zealand kina (Evechinus chloroticus) have also been heavily fished. However, there are large numbers of poor quality (low gonad index or GI) kina found in kina barrens which are uneconomic to harvest due to low returns. The primary aim of this research was to identify the key holding and environmental conditions for roe enhancement of E. chloroticus to assist in the development of a roe enhancement industry for E. chloroticus to utilise this resource. A series of experiments testing the optimal holding conditions for E. chloroticus in both land- and sea-based holding systems showed that culture depth (3 and 6 m) and removal of the urchins from the water three times per week had no significant effect on gonad growth or urchin mortality. However, exposing E. chloroticus to increased water movement resulted in significantly greater gonad growth in 12 weeks. Increasing water movement is believed to increase the available dissolved oxygen and facilitate the removal of metabolites from around the urchins. Gonad development was not negatively impacted at the maximum stock density tested (6 kg urchin m-2 of internal surface area) and this density is recommended. There are significantly lower running and maintenance costs when E. chloroticus are enhanced in sea-based compared to land-based systems but a full economic analysis is required to assess which is likely to be the more economical option for future roe enhancement. A period of 9 to 12 weeks appears to be the optimal period for roe enhancement in terms of the maximum increase in GI in the shortest time period. Repeated experiments over a 12 month period showed that food availability was the primary driver of roe enhancement (i.e. increase in gonad size) in E. chloroticus. This is followed by seawater temperature, which drives much of the seasonal variation in the gonad size that is observed in wild urchins. This is likely to be due to increased food consumption at higher temperatures. The reproductive stage of E. chloroticus had very little effect on the increase in gonad size of enhanced urchins other than in autumn when gonad growth was slightly lower than in all other seasons. Optimal gonad growth in this study was obtained at 18oC, which was the highest temperature tested. Higher temperatures also resulted in an increase in the rate of progress of the gametogenic cycle of E. chloroticus whilst lower temperatures tended to slow the rate of progress. The effects of temperature on gonad growth (i.e. increased growth at higher temperatures) were consistent across seasons. Photoperiod had minimal effect on gonad growth and the reproductive stage of the urchins over periods of 12 weeks. Photoperiod may still affect gametogenesis of E. chloroticus over longer periods. Low GI kina appear to be capable of significantly larger increases in GI in 10-week periods than high GI kina, as a result of their higher tolerance to stress. This thesis has contributed to improving the technical and economic feasibility of roe enhancement of kina (E. chloroticus) in New Zealand.</p>


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jiangnan Sun ◽  
Zihe Zhao ◽  
Chong Zhao ◽  
Yushi Yu ◽  
Peng Ding ◽  
...  

AbstractInteraction among sea urchins remains largely uninvestigated, although the aggregation of sea urchins is common. In the present study, 1, 15 and 30 sea urchins Strongylocentrotus intermedius (11.06 ± 0.99 mm in test diameter) were placed in a 1 m2 circular tank, respectively. Movement behaviors were recorded for 12 min to investigate potential interactions among sea urchins. After the 12-min control period, we added food cues into the tank and recorded the changes in sea urchins’ behaviors. For the first time, we here quantified the interactions among sea urchins in laboratory and found that the interactions varied with food cues and with different densities. The sea urchins dispersed in random directions after being released. There was no significant difference in the movement speed and the displacement of sea urchins among the three density groups (1, 15 and 30 ind/m2). The interaction occurred when sea urchins randomly contacted with the conspecifics and slowed down the movement speed. The speed of sea urchins after physical contacts decreased by an average of 40% in the density of 15 ind/m2 and 17% in the density of 30 ind/m2. This interaction resulted in significantly higher randomness in the movement direction and lower movement linearity in 15 and 30 ind/m2 than in 1 ind/m2. After the introduction of food cues, the movement speed, displacement and dispersal distance of sea urchin groups decreased significantly in all the three densities. The dispersal distance and expansion speed of sea urchins were significantly lower in 30 ind/m2 than those in 15 ind/m2. The present study indicates that the interaction among sea urchins limits the movement of individual sea urchin and provides valuable information into how large groups of sea urchins are stable in places where food is plentiful.


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