scholarly journals ASPEK REPRODUKSI IKAN LOUHAN HIBRID SEBAGAI IKAN ASING INVASIF DI DANAU MATANO, SULAWESI SELATAN

2018 ◽  
Vol 10 (2) ◽  
pp. 69
Author(s):  
Dimas Angga Hedianto ◽  
Agus Arifin Sentosa ◽  
Hendra Satria
Keyword(s):  
Alien Species ◽  
Invasive Alien Species ◽  
Gravimetric Method ◽  
Habitat Characteristics ◽  
Maturity Stage ◽  
South Sulawesi ◽  
Gill Net ◽  
Sandy Rock ◽  
Total Fecundity ◽  
First Maturity

Penelitian mengenai aspek reproduksi ikan asing invasif di Danau Matano dibutuhkan dalam upaya pengendalian dan pemberantasan populasinya. Penelitian ini bertujuan untuk mengetahui aspek reproduksi ikan louhan yang diharapkan dapat digunakan sebagai acuan untuk pengendalian ikan asing invasif di Danau Matano, Sulawesi Selatan. Sampel ikan diperoleh dengan menggunakan jaring insang percobaan dengan berbagai ukuran mata jaring pada Mei dan Oktober 2015 serta pada Februari, Juli, dan September 2016 di 14 stasiun penelitian. Penentuan jenis kelamin dan tingkat kematangan gonad (TKG) berdasarkan ciri reproduksi primernya. Fekunditas total dihitung menggunakan metode gravimetrik. Ikan louhan yang tertangkap sebanyak 1.118 ekor terdiri atas 552 ekor ikan jantan, 512 ekor ikan betina, dan 54 ekor tidak dapat ditentukan jenis kelaminnya. Nisbah kelamin secara temporal berada pada kondisi seimbang dengan perbandingan total sebesar 1,1:1. Ikan louhan jantan dan betina mencapai rata-rata ukuran pertama kali matang gonad (Lm50) masing-masing pada panjang total 12,6 cm dan 10,2 cm. Ikan jantan berukuran lebih besar daripada betina pada TKG yang sama. Diameter telur berkisar antara 0,25-2,35 mm (rerata 1,31±0,37 mm) dengan fekunditas berkisar antara 104-3.375 butir. Ikan louhan termasuk tipe pemijah bertahap dan mampu memijah sepanjang tahun di berbagai tipe karakteristik habitat. Puncak pemijahan terjadi pada musim penghujan dan kemarau. Substrat dasar berupa pasir berbatu di kedalaman 15 meter merupakan daerah utama pemijahan ikan louhan di Danau Matano. Rekomendasi pengendalian ikan louhan di Danau Matano melalui penangkapan perlu dilakukan sebelum mencapai ukuran Lm50, di seluruh daerah litoral danau (<10 meter) pada musim kemarau (April-Juni) dan penghujan (September-November).The information on fish reproduction aspects of invasive alien species in Matano Lake is required to setup measure for controlling and eradicating their population. This research aims to determine the reproductive aspects of flowerhorn cichlid that could used as a reference for controlling the invasive alien species in the Matano Lake, South Sulawesi. Sample was collected by using experimental gill-net with various mesh sizes in 14 research stations in several periods (May 2015, October 2015, February 2016, July 2016, and September 2016). Sex determination and gonadal stages identified based on the characteristics of primary reproduction. Total fecundity is calculated using gravimetric method. The total individual flowerhorn cichlid was 1,118 fishes that consists of 552 males, 512 females, and 54 unidentified. The temporary sex ratio indicated balance conditions by ratio 1.1:1. Length at first maturity (Lm50) of male and female of flowerhorn cichlid reached at 12.6 cmTL and 10.2 cmTL, respectively. Males are larger than females at the same gonad maturity stage. The eggs diameter ranged from 0.25 to 2.35 mm (average of 1.31 ± 0.37 mm) with fecundity ranged from 104-3,375 egg which indicated that flowerhorn cichlid was a partial spawner. Flowerhorn cichlid spawned throughout the year (multi spawning) in various types of habitat characteristics with spawning peaks in the rainy and dry seasons. Sandy rock in the depth of 15 meters is the main of spawning area of flowerhorn cichlid in the Matano Lake. The recommendation for controlling flowerhorn cichlid in Matano Lake by fishing, need to be done before its size reaching the Lm50, across the littoral area of the lake (<10 meters) in the dry (April-June) and rainy seasons (September-November).

Conservation, Ecology, and Management of Catfish: The Second International Symposium

2011 ◽  
Keyword(s):  
Gulf Of California ◽  
Average Length ◽  
Gonad Development ◽  
Maturity Stage ◽  
Important Species ◽  
Conservation Ecology ◽  
Gill Net ◽  
Negative Effect ◽  
First Maturity ◽  
Fishing Practices

<em>Abstract</em>.—The chihuil sea catfish <em>Bagre panamensis </em>from the southeastern Gulf of California is an important species that is commercially exploited. Currently, the species is thought to have relatively high abundances. However, studies on biology of this species are scarce; therefore, harvest regulations do not exist for this species in Mexico. The aim of this work was to describe reproductive biology of this species as an initial basis for management of this resource, to assess if the current fishing practices could have an effect on its population, and finally, to begin promoting effective management of this population. Gill-net samples were carried out from October 2008 to October 2009. All fish were dissected; gender and gonad maturity stage were determined macroscopically. Results indicated that the spawning season runs from May to August and generally with synchronic gonad development. Fecundity of the chihuil sea catfish was 36, which is low because this species shows parental care via oral incubation of fry, reducing mortality. Estimated length at first maturity is 350 mm total length (TL). Average length at first catch from the artisanal gill-net fishery is 300 mm TL, indicating that this fishery is harvesting fish that have yet to have had a single reproductive event. A large number of captured fish consisted of males that were incubating fry, thus, likely causing large fry mortality. Current harvest practices may have a negative effect on the chihuil sea catfish population in the Gulf of California. A closed season is proposed for this species from May to August with a minimum harvest length of 400 mm TL.

scholarly journals Biologi reproduksi ikan kembung lelaki, Rastreliger kanagurta (Cuvier, 1816) di perairan pesisir Takalar, Sulawesi Selatan

2018 ◽  
Vol 17 (3) ◽  
pp. 259
Author(s):  
Mauli Kasmi ◽  
Syamsul Hadi ◽  
Wayan Kantun
Keyword(s):  
Coastal Waters ◽  
Gravimetric Method ◽  
Maturity Stage ◽  
Gonad Weight ◽  
Gonad Maturity ◽  
Indian Mackerel ◽  
Mature Gonad ◽  
Total Fecundity ◽  
Method Analysis ◽  
Somatic Index

The objective of this research is to observe reproductive biology of Indian mackerel in Takalar coastal waters through gonad maturity development, the first size of mature gonad, spawning, gonado somatic index (GSI), and fecundity. Sampling was done for eight months started from March to October 2015. Gonad maturity stage was observed morphologically, spawning season focusing on direct observation result toward gonad by identifying Indian mackerel which has spawned.GSI was analyzed based on comparison between gonad weight and Indian mackerel weight while fecundity was observed by gravimetric method. Analysis result shows that Indian mackerel gonad maturity throughout the year with peak occurring in July and August. GSI was around 0,928-4,490. The first size of gonad mature of female Indian mackerel is 21,18 cm and male Indian mackerel is 21,31 cm. Spawning occurs after peak of gonad maturity so next month, value of maturity index decreases slowly and gradually. Indian mackerel has total fecundity around 11.235- 40.878 granule. AbstrakPenelitian ini bertujuan untuk mengamati biologi reproduksi ikan kembung lelaki di perairan pesisir Takalar melalui perkembangan kematangan gonad, ukuran pertama matang gonad, musim pemijahan, indeks kematangan gonad (IKG), dan fekunditas. Pengambilan sampel dilakukan selama delapan bulan mulai Maret sampai Oktober 2015. Perkembang-an kematangan gonad diamati secara morfologi. Musim pemijahan mengacu pada hasil pengamatan langsung terhadap gonad dengan mendata ikan kembung lelaki yang telah memijah. IKG dianalisis berdasarkan perbandingan antara bobot gonad dan bobot tubuh ikan kembung lelaki, sedangkan fekunditas dihitung dengan metode gravimetrik. Hasil analisis menunjukkan bahwa ikan kembung lelaki mengalami kematangan gonad sepanjang tahun dengan puncak terjadi pada bulan Juli dan Agustus. IKG berkisar 0,928-4,490. Ukuran ikan kembung lelaki betina kali pertama matang gonad adalah 21,18 cm dan jantan adalah 21,31 cm. Pemijahan terjadi setelah puncak kematangan gonad sehingga pada bulan berikutnya terjadi penurunan nilai indeks kematangan secara perlahan dan bertahap. Ikan kembung lelaki memiliki fekunditas total berkisar 11.235-40.878 butir.

scholarly journals PENDEKATAN POLA PEREMAJAAN DAN LAJU EKSPLOITASI IKAN LOUHAN UNTUK PENGENDALIAN IKAN ASING INVASIF DI DANAU MATANO, SULAWESI SELATAN

2018 ◽  
Vol 23 (4) ◽  
pp. 227
Author(s):  
Dimas Angga Hedianto ◽  
Hendra Satria
Keyword(s):  
Mortality Rate ◽  
Alien Species ◽  
Invasive Alien Species ◽  
Total Mortality ◽  
Growth Equation ◽  
Recruitment Pattern ◽  
Lake Matano ◽  
South Sulawesi ◽  
Exploitation Rate ◽  
Annual Total

Ikan louhan tergolong jenis ikan hibrid (sehingga tidak dapat ditentukan nama ilmiahnya) dari famili Cichlidae yang terindikasi sebagai ikan asing invasif di Danau Matano. Keberadaan ikan tersebut di Danau Matano perlu dikaji dan dikendalikan untuk menjaga kelestarian keanekaragaman hayati jenis ikan endemik. Penelitian ini bertujuan untuk menganalisis pola peremajaan dan laju eksploitasi ikan louhan sebagai pendekatan dalam pengendalian ikan asing invasif di Danau Matano, Sulawesi Selatan. Analisis data dilakukan terhadap 2.931 ekor ikan louhan yang ditangkap menggunakan jaring insang percobaan berbagai ukuran mata jaring dilengkapi data enumerator secara bulanan pada bulan Februari hingga November 2016 dengan bantuan perangkat lunak FiSAT II. Hasil analisis menunjukkan bahwa pola pertumbuhan ikan louhan di Danau Matano bersifat alometrik positif. Pertumbuhan mengikuti persamaan Lt=23,67[1-e0,41(t+0,4281)]. Umur maksimum (tmax) mencapai 7,32 tahun dengan performa pertumbuhan (Ø’) sebesar 2,36. Laju mortalitas total (Z) tahunan didapatkan sebesar 1,46 tahun-1. Laju mortalitas penangkapan tahunan (F = 0,38 tahun-1) lebih rendah daripada laju mortalitas alami tahunan (M = 1,08 tahun-1). Laju eksploitasi (E) ikan louhan di Danau Matano hanya sebesar 0,26 tahun-1 dimana menunjukkan bahwa upaya pemanfaatannya masih sangat rendah. Pola peremajaan terjadi dua kali dalam setahun, yaitu pada Mei (16,19%) dan Oktober (6,05%). Upaya pengendalian ikan louhan sebagai ikan invasif di Danau Matano perlu dilakukan pada saat puncak peremajaan tertinggi secara berkesinambungan disertai peningkatan laju eksploitasi e” 48% dari upaya yang ada, terutama pada April-Mei dan September-Oktober di daerah litoral perairan danau.Flowerhorn cichlid is classified as hybrid species (so that the scientific name can’t be determined) from Cichlidae which indicated as invasive alien fish in Lake Matano. The existence of flowerhorn in Lake Matano need to be assessed and controlled to preserve the biodiversity of endemic fish species. This research aims to assess recruitment pattern and utlization status of flowerhorn cichlid for controlling of invasive alien species at Lake Matano, South Sulawesi. Data analysis was carried out on 2,931 flowerhorn Cichlid caught using experimental gillnets of various mesh sizes included enumerators data which recorded monthly from February to November 2016 using FiSAT II software. The analysis resulted the growth pattern of flowerhorn cichlid in Matano louhan Lake was positive allometric. The growth equation of flowerhorn cichlid was Lt=23.67[1-e0,4(t+0.4281)]. Longevity (tmax) attained 7.32 years with growth performance (Ø’) was 2.36. The annual total mortality rate (Z) obtained 1.46 years-1. The annual fishing mortality rate (F = 0.38 years-1) is lower than the annual natural mortality rate (M = 1.08 years-1). Exploitation rate (E) of flowerhorn cichlid in Lake Matano only 0.26 years-1, which was indicated under exploitation. Recruitment pattern occurs twice a year, in May (16.19%) and October (6.05%). The eradication efforts to control population of flowerhorn cichlid as invasive alien species in Lake Matano needs to be done at the peak of recruitment and also increased exploitation rate about e” 48% of existing efforts, especially on April-May and September-October in the littoral area of Lake Matano.

scholarly journals Introduction and Spread of the Invasive Alien Species Ageratina altissima in a Disturbed Forest Ecosystem

2021 ◽  
Vol 13 (11) ◽  
pp. 6152
Author(s):  
Eunyoung Kim ◽  
Jaeyong Choi ◽  
Wonkyong Song
Keyword(s):  
Land Use ◽  
South Korea ◽  
Alien Species ◽  
Invasive Alien Species ◽  
Management Policy ◽  
Economic Damage ◽  
Forest Edges ◽  
Forest Interior ◽  
Lower Elevation ◽  
Canopy Area

Invasive alien species (IAS) not only displace nearby indigenous plants and lead to habitat simplification but also cause severe economic damage by invading arable lands. IAS invasion processes involve external forces such as species characteristics, IAS assemblage traits, environmental conditions, and inter-species interactions. In this study, we analyzed the invasion processes associated with the introduction and spread of Ageratina altissima, a representative invasive plant species in South Korea. We investigated 197 vegetation quadrats (2 × 20 m) in regions bordering 47 forests in southern Seoul and Gyeonggi-do, South Korea. A total of 23 environmental variables were considered, which encompassed vegetation, topography, land use, and landscape ecology indices. The model was divided into an edge and an interior model and analyzed using logistic regression and a decision tree (DT) model. The occurrence of Ageratina altissima was confirmed in 61 sites out of a total of 197. According to our analysis, Ageratina altissima easily invaded forest edges with low density. The likelihood of its occurrence increased with lower elevation and gentler slope. In contrast, the spread of Ageratina altissima in the forest interior, especially based on seed spread and permeability, was favored by a lower elevation and gentler slopes. The analysis of Ageratina altissima settlement processes in forest edges coupled with the DT model demonstrated that land characteristics, such as the proximity to urbanized areas and the number of shrub and tree species, play a pivotal role in IAS settlement. In the forest interior, Ageratina altissima did not occur in 68 of the 71 sites where the soil drainage was under 2.5%, and it was confirmed that the tree canopy area had a significant impact on forest spread. Based on these results, it can be assumed that Ageratina altissima has spread in South Korean forests in much the same way as other naturalized species. Therefore, vegetation management strategies for naturalized species should be developed in parallel with land use management policy in regions surrounding forest edges to successfully manage and control Ageratina altissima invasion.

scholarly journals InvasionDB: A genome and gene database of invasive alien species

2021 ◽  
Vol 20 (1) ◽  
pp. 191-200
Author(s):  
Cong HUANG ◽  
Kun LANG ◽  
Wan-qiang QIAN ◽  
Shu-ping WANG ◽  
Xiao-mei CAO ◽  
...  
Keyword(s):  
Alien Species ◽  
Invasive Alien Species ◽  
A Genome ◽  
Gene Database

Invasive Alien Species in Malaysia

2021 ◽  
pp. 151-167
Author(s):  
Ibrahim Faridah‐Hanum ◽  
Abdul Latiff
Keyword(s):  
Alien Species ◽  
Invasive Alien Species
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