scholarly journals Some reproductive biology aspects of bonylip barb (Osteochilus vittatus Valenciennes, 1842) in the waters of Benanga Reservoir, East Kalimantan

2020 ◽  
Vol 20 (3) ◽  
pp. 217
Author(s):  
Jusmaldi Jusmaldi ◽  
Nova Hariani ◽  
Medi Hendra ◽  
Nikmahtulhaniah Ayu Wulandari ◽  
Sarah Sarah
Keyword(s):  
Sex Ratio ◽  
Reproductive Biology ◽  
Mesh Size ◽  
Spawning Season ◽  
Mature Stage ◽  
Fish Stock ◽  
Male And Female ◽  
Gonad Maturity ◽  
East Kalimantan ◽  
Egg Diameter

Bonylip barb (Osteochilus vittatus Valenciennes, 1842) that belongs to the Cyprinidae family is one of the native freshwater fishes in Indonesian waters. Currently, status of this species in Benanga Reservoir, East Kalimantan is in over-exploited. Fish resources management, therefore, is needed to maintained fish stock in the reservoir based on fish reproductive biology aspects. The purpose of this study was to analyze some aspects of the reproductive biology including sex-ratio, gonad maturity, length at first gonad maturity, spawning season, fecundity, and spawning patterns as basic information for its management. Fish collection was carried out monthly on the third week from January to May 2019 at three stations. The fish samples were captured by using experimental gill nets with mesh size of 1; 1.5; 2; and 3 inches. A total of 278 bonylip barb was caught, consist of 92 males and 186 females. Sex ratio of male and female in the gonad mature stage was 1: 2.4. The average length at first gonad maturity in male and female were 136.08 mm and 137.38 mm, respectively. Peak of spawning occurs during the rainy season in May, with more than 90% of fish in mature stage with GSI in male and female were 6.88%, 13.16% respectively. Total fecundity ranged from 7312-22923 eggs individual-1 and egg diameter ranged from 0.6-1.94 mm. According to distribution of egg diameter, bonylip barb was categoried as a total spawner. Some management strategies that can be carried out are using fishing gears with mesh size above 2 inches, limiting fishing activities in the peak of the spawning season, prohibiting fishing gear using electric shocker and protection the reservoir from erosion.

scholarly journals Reproductive biology of silurid catfishes Ompok miostoma (Vaillant 1902) in Mahakam River East Kalimantan

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
. Jusmaldi ◽  
Dedy Duryadi Solihin ◽  
Ridwan Affandi ◽  
MF Rahardjo ◽  
Rudhy Gustiano
Keyword(s):  
Sex Ratio ◽  
Reproductive Biology ◽  
Spawning Season ◽  
Spawning Period ◽  
Male And Female ◽  
Gonad Maturity ◽  
East Kalimantan ◽  
Fish Samples ◽  
Total Fish ◽  
Somatic Index

Reproductive biology of silurid catfish O.miostoma(Vaillant 1902)as one of endemic species in Mahakam River East Kalimantan is not yet known. This study aimed to analysisreproductive aspect related to changing seasons, including sex-ratio, spawning season, spawning location, length at first gonad maturity, gonado-somatic index, and fecundity. Total fish samples (n=1214)were collected monthly from November 2013 to October 2014 at four locations in the Mahakam River, using many fishing gears.The results of this research showthe total length of fish ranged from 132.19 to 227.30 mm and weight ranged from 20.00 to 70.40 g. The overall sex ratio of male and female was1: 1.56, while at gonad maturity stages were1:1.77. The spawning season range from November to January and peak spawning occurs in December. The highest spawning location was found at swamp flood Semayang Lake. The length at first gonad maturity of male ranged of 191.05-202.60 mm, while it was in 179.56-198.50 female. Maximum average gonado-somatic index (GSI) values obtained for male and female were 0.32 and 2.07 respectively during spawning period in November and declined to minimum in February. The total fecundity and eggs diameter rangedfrom 2648 to 12495 eggsind-1and 0.61 to 1.30 mm respectively. There was a positive correlation between fecundity andtotal length and weightof fishes.AbstrakBiologi reproduksi ikan lais O. miostoma (Vaillant 1902)sebagai salah satu spesies endemik di Sungai Mahakam Kalimantan Timur belum pernah diketahui. Tujuan penelitian ini adalah menganalisisaspek reproduksi ikan laisberkaitan dengan perubahan musimyang mencakupnisbah kelamin, musim pemijahan, lokasi pemijahan, ukuran kali pertama matang gonad, indeks kematangan gonad dan fekunditas.Total ikan contoh 1214 ekor telah dikumpulkan setiap bulan mulai dari bulan November 2013 sampai Oktober 2014di empat lokasi perairan Sungai Mahakam, menggunakan berbagai alat tangkap. Hasil penelitian menunjukkanukuran panjang total ikan berkisar dari 132,19-227,30 mm dan bobot berkisar dari  20,00-70,40 gram.Nisbah kelamin seluruh ikan jantan dan betina yang diamati 1 : 1,56, sedangkanpada tahap kematangan gonad 1:1,77. Musim pemijahan terjadi mulai dari bulan November sampai Januari dan puncak pemijahan pada bulan Desember. Lokasi pemijahan tertinggi ditemukan di rawa banjiran Danau Semayang. Ukuran ikan pertamamatang gonad pada jantan berkisar dari 191,05-202,60 mm dan betina berkisar dari 179,56-198,50 mm. Rata-rata indeks kematangan gonad (IKG)  tertinggi ditemukan pada jantan dan  betina berturut turut 0,32  dan 2,07 selama musim pemijahanpada bulan November dan menurun hingga terendah pada bulan Februari. Fekunditas total berkisar dari 2.648-12.495 butir telur per individu.Ada korelasi positif antara fekunditas dengan panjang total dan bobot ikan.

scholarly journals HUBUNGAN PANJANG-BOBOT DAN FAKTOR KONDISI IKAN NILEM (Osteochilus vittatus VALENCIENNES, 1842) DI PERAIRAN WADUK BENANGA, KALIMANTAN TIMUR

2020 ◽  
Vol 19 (2) ◽  
Author(s):  
Jusmaldi Jusmaldi ◽  
Nova Hariani ◽  
Nikmahtulhaniah Ayu Wulandari
Keyword(s):  
Body Weight ◽  
Sex Ratio ◽  
Condition Factor ◽  
Mesh Size ◽  
Growth Patterns ◽  
Male And Female ◽  
Tropical Regions ◽  
Weight Relationship ◽  
East Kalimantan ◽  
Gill Net

Biology of bonylip barb (Osteochilus vittatus Valenciennes, 1842) in Benanga Reservoir, East Kalimantan is not yet known. The purpose of this study was to analyze distribution of the length and body weight of fishes, sex ratio, gonad maturity level, length-body weight relationship, and condition factor. In total 278 fishes samples were collected during the five months, from January to May 2019 with a purposive sampling method at Benanga Reservoir, and gill net with  mesh size 0.5; 1; and 1.5  inches used. The results of this research showed that the total length of the fishes analyzed ranged from 72.21–196.57 mm and body weight ranged from 5.12–89.21 g. The sex ratio of male and female were 1:2.02. The male and female fishes were dominated by mature gonad. The length-body weight relationship models calculated for the total fishes sample was W=1x10-5L2.967 (r=0.988) for males, W=5x10-6L3.199 (r=0.989) for females and W=7x10-6L3.126 (r=0.987) for both sexes. Isometric growth patterns (b=3) were observed in males, meanwhile positive allometric growth patterns (b>3) were observed in females and both sexes. Calculation of the condition factor (K) resulted in 1.181±0.117 for males, 0.949±0.094 for females, and 1.026±0.150 for all specimens. The condition factors of bonylip barb from the Benanga Reservoir inside the range recommended as suitable for freshwater fish species in the tropical regions.   

scholarly journals Gonad maturity of simping Placuna placenta, Linn 1758 (Bivalve: Placunidae) harvested from Kronjo Coastal, Indonesia

2019 ◽  
Vol 5 (1) ◽  
pp. 26-37
Author(s):  
Yon Yonvitner ◽  
Isdradjad Setyobudiandi ◽  
Rokhmin Dahuri ◽  
Jamilah Jamilah
Keyword(s):  
Sex Ratio ◽  
Shallow Water ◽  
Shell Length ◽  
Raw Material ◽  
Mature Stage ◽  
Male And Female ◽  
Gonad Maturity ◽  
Coastal Resource ◽  
Males And Females

Simping (P. placenta) is a coastal resource found in shallow water with a muddy substrate. Simping widely used as a source of food and as raw material for the decoration.  Utilization of simping until now has not yet focused on recruitment, reproductive aspect. This information is important as a basis data for determining the size of the simping catch. This study aimed to find out about of reproduction aspect, determining sex ratio the size of the catch simping. This research was conduct for three months at 3 locations. The number of samples in the analysis is 36 species to determine sex ratio and gonad maturity.  Sex ratio indifferent from male and female, but based on the time sex ratio of simping significant, both male and female. The length size of gonads shellfish matures form 5.50 cm and 5.85 cm at 2 TKG conditions. Length of simping mature from 6.08 cm, 6.24 cm, 6.45 cm and 7.11 cm dominant at TKG mature stage 3,  and 8.61 cm dominant at 4 TKG conditions. Sex ratio reaches 6 cm shell length and not significant between males and females (M: F=1;1).  It is concluded that  the level of maturity of gonads increases  with increasing of simping size. 

scholarly journals POTENSI REKRUT IKAN BONTI-BONTI (Paratherina striata Aurich) DI DANAU TOWUTI, SULAWESI SELATAN

2017 ◽  
Vol 3 (1) ◽  
pp. 45
Author(s):  
Syahroma Husni Nasution ◽  
Ismudi Muschsin ◽  
Sulistiono Sulistiono
Keyword(s):  
Sex Ratio ◽  
Animal Feed ◽  
Raw Material ◽  
Maturity Index ◽  
Male And Female ◽  
Gonad Maturity ◽  
Average Value ◽  
Index Value ◽  
Egg Diameter ◽  
Lake Towuti

Ikan bonti-bonti (Paratherina striata) selain endemik, statusnya tergolong rawan punah (vulnerable species) dan hanya terdapat di Danau Towuti dan Danau Mahalona. Masyarakat di sekitar danau memanfaatkan ikan ini sebagai ikan konsumsi, ikan hias, dan bahan pakan hewan. Populasi ikan ini dikhawatirkan mengalami penurunan, diduga karena degradasi kualitas lingkungan dan penangkapan ikan yang cenderung intensif. Penelitian ini bertujuan untuk mengkaji potensi rekrut ikan bonti-bonti sebagai dasar pengelolaannya. Pengamatan dilakukan di Danau Towuti setiap bulan selama 12 bulan dari bulan Mei 2006-April 2007. Contoh ikan diperoleh menggunakan jaring insang eksperimental dengan ukuran mata jaring 0,625, 0,75, 1,0, dan 1,25 inci yang dioperasikan di lima stasiun (Tanjung Bakara; inlet Danau Towuti; Pulau Loeha; outlet Danau Towuti dan Beau). Potensi rekrut ikan dapat dilihat dari nisbah kelamin, diameter telur, fekunditas, dan indeks kematangan gonad. Hasil penelitian memperlihatkan bahwa nisbah kelamin total ikan bonti-bonti jantan dan betina 1,0:0,9. Fekunditasikan bonti-bonti 818-6.051 butir. Diameter telur ikan bonti-bonti berkisar antara 0,01-1,50 mm. Nilai indeks kematangan gonad ikan bonti-bonti jantan dan betina paling tinggi dijumpai di stasiun II, masing-masing 3,96 dan 6,77%. Ditinjau dari fekunditas, potensi rekrut ikan bonti-bonti lebih tinggi dibandingkan ikan Telmatherinidae lain. Secara temporal, nilai rata-rata indeks kematangan gonad tertinggi pada ikan jantan terjadi pada bulan Mei dan Nopember dengan nilai 2,09±1,36% dan 1,85±1,06%, demikian pula pada ikan betina dengan nilai 3,39±1,47 dan 3,47±1,37%. Rekruitmen ikan bonti-bonti terjadi setiap bulan dengan periode tertinggi antara bulan Oktober-Nopember. Bonti-bonti (Paratherina striata), is one of endemic and vulnerable fish in Lake Towuti and Mahalona. Bonti-bonti have been utilized by people around the lake as consumption fish; ornamental fish and as raw material for animal feed. The population tend to decrease due to environmental quality deterioration and increasing exploitation. This study was aimed to reveal the recruit potential of bontibonti as the foundation for its management. This research was conducted in Lake Towuti, South Sulawesi from May 2006 to April 2007. Samples were collected monthly at five stations (Tanjung Bakara; Inlet of Lake Towuti; Pulau Loeha; Outlet of Lake Towuti, and Beau) using experimental gillnet sized 0.625, 0.75, 1.0, and 1.25 inches. Recruitment potential could be evaluated from sex ratio, egg diameter, fecundity, and gonad maturity index. Total sex ratio of male and female bonti-bonti are 1.0:0.9. Fecundity of bonti-bonti are 818-6.051. Egg diameter of bonti-bonti range from 0.01-1.50 mm. Gonad maturity index value of male and female was found highest at station II (inlet of Lake Towuti) as high as 3.96 and 6.77% respectively. Based on fecundity, recruitment potential of bontibonti is higher compared to the other Telmatherinid. Temporally, the average value of gonad maturity index was found highest on male in May and November with the values of 2.09±1.36% and 1.85±1.06%, and for female with the values of 3.39±1.47 and 3.47±1.37%. Fish recruitment occured each month with the highest period occur in October-November.

scholarly journals REPRODUCTIVE ASPECTS OF SCALLOPED PERCHLET, Ambassis nalua (HAMILTON, 1822) IN PABEAN BAY INDRAMAYU, WEST JAVA

2017 ◽  
Vol 9 (1) ◽  
pp. 113-124 ◽  
Author(s):  
Nisha Desfi Arianti ◽  
M.F. Rahardjo ◽  
Ahmad Zahid
Keyword(s):  
Sex Ratio ◽  
Sampling Period ◽  
Spawning Season ◽  
Diameter Distribution ◽  
Male And Female ◽  
Fish Samples ◽  
Males And Females ◽  
Mature Fish ◽  
First Maturity ◽  
Egg Diameter

ABSTRACTScalloped perchlet, Ambassis nalua,  is one of fishes in Pabean Bay, Indramayu. This research aims to determine the reproductive aspects of Ambassis nalua in Pabean Bay Indramayu including sex ratio, spawning season, first maturity, fecundity and spawning pattern. Fish samples were collected by trap net and trammel net at three sites in Pabean Bay from April to October 2015. A total of 424 of A. nalua were caught, consist of 114 males and 310 females; with total length ranged from 38.04 to 112.63 mm and total weight ranged from 0.37 to 25.44 g. Sex ratio of mature fish  was 1:1.9. The mature males and females were found in every month of sampling period. The gonado-somatic index (GSI) ranged from 0.40 to 0.83 and 2.36 to 4.54 for male and female, respectively. The peak of spawning season was found in September. The first maturity (Lm50) for male and female were 79.17 mm and 91.25 mm, respectively. The fecundity varied from 3,451–32,465 eggs. Egg diameter distribution shows that spawning pattern of A. nalua was batch spawner. Keywords: Ambassis nalua, spawning season, sex ratio, reproduction

scholarly journals Hubungan panjang bobot dan faktor kondisi ikan wader bintik dua Barbodes binotatus (Valenciennes, 1842) di Sungai Barambai Samarinda Kalimantan

2019 ◽  
Vol 18 (2) ◽  
pp. 87 ◽  
Author(s):  
. Jusmaldi ◽  
Nova Hariani
Keyword(s):  
Sex Ratio ◽  
Condition Factor ◽  
Mean Value ◽  
Male And Female ◽  
Weight Relationship ◽  
Total Length ◽  
East Kalimantan ◽  
Fish Samples

Biology of the spotted barb Barbodes binotatus (Valenciennes, 1842) in Barambai River, east Kalimantan is unknown. This study aimed to analyses sizes of fish, sex ratio, length-weight relationship and condition factor of the spotted barb. A total of 347 fish samples were collected by several gears in Barambai River from August to October 2017. The results of this research showed that the total length of the fish ranged from 45.67 to 146.01 mm and weight ranged from 1.27-43.34 g. The sex ratio of male and female were 1:1.12. The length-weight equations for males was W = 1x10-5 L3.063, W = 8x10-6L3.108 for females, and W = 9 x 10-6 L3.091 for both sexes. The condition factor (K) for the spotted barb was ranged between 0.826 – 2.214 with mean value of 1.163.  AbstrakBiologi ikan wader bintik dua Barbodes binotatus (Valenciennes, 1842) di Sungai Barambai, Kalimantan Timur belum diketahui. Penelitian ini bertujuan menganalisis ukuran ikan, nisbah kelamin, hubungan panjang bobot, dan faktor kon-disi. Total 347 sampel ikan dikumpulkan dengan menggunakan berbagai alat tangkap di Sungai Barambai dari bulan Agustus sampai Oktober 2017. Hasil penelitian menunjukkan bahwa panjang total ikan berkisar dari 45,67 sampai 146,01 mm dan bobot tubuh berkisar 1,27- 43,34 gram. Nisbah kelamin jantan dan betina 1: 1,12. Model hubungan panjang bobot ikan jantan W = 1x10-5 L3,063, ikan betina W = 8x10-6L3,108,dan keseluruhan jenis ikan W =  9 x 10-6  L3,091. Faktor kondisi (K) ikanwader bintik dua berkisar antara 0,826 - 2,214 dan rata-rata 1,163. 

scholarly journals Some Aspects of Reproductive Biology of the Mudskipper Apocryptes Bato From the Coast of Chitagong

2018 ◽  
Vol 44 (1) ◽  
pp. 91-99
Author(s):  
Mohammed Sadequer Rahman ◽  
Md Sohel Parvez ◽  
Mohammad Mizanur Rahman ◽  
Md Rashed Un Nabi ◽  
Md Wahidul Alam
Keyword(s):  
Reproductive Biology ◽  
Coastal Waters ◽  
Spawning Season ◽  
Gonad Weight ◽  
Male And Female ◽  
Length Standard ◽  
Significant Coefficient ◽  
The Right ◽  
T Values ◽  
Relationship Of

Some aspects of reproductive biology of the mudskipper Apocryptes bato (Hamilton 1822) from the coastal waters of Chittagong, Bangladesh was conducted. Disproportionate occurrence of male and female (1.20 : 1) was observed in the number of two sexes. A prolonged spawning season was found from June to early October with a single peak. The aspects in the ovary indicate one complete spawning of females in a single spawning season. The fecundity was found to vary from 7453 - 31195 with an average of 17590 ± 6867. Significant coefficient of correlation between the diameters of the eggs of corresponding anterior, middle and posterior regions of the right and left ovaries indicated the simultaneous release of eggs from both the ovaries. A much closer relationship of fecundity and the significant ‘t’ values indicated fecundity increases with the increase of total length, standard length, body weight and gonad weight. Asiat. Soc. Bangladesh, Sci. 44(1): 91-99, June 2018

scholarly journals BIOLOGI REPRODUKSI IKAN BETOK (Anabas testudineus) DI PAPARAN BANJIRAN LUBUK LAMPAM,KABUPATEN OGAN KOMERING ILIR

2015 ◽  
Vol 6 (3) ◽  
pp. 137
Author(s):  
Eko Prianto ◽  
Mohammad Mukhlis Kamal ◽  
Ismudi Muchsin ◽  
Endi Setiadi Kartamihardja
Keyword(s):  
Sex Ratio ◽  
Anabas Testudineus ◽  
Commercial Fish ◽  
Male And Female ◽  
Climbing Perch ◽  
Male Sex ◽  
First Maturity ◽  
Egg Diameter ◽  
Floodplain Area ◽  
Somatic Index

Ikan betok (Anabas testudineus) adalah salah satu jenis ikan ekonomis penting yang dihasilkan dari perairan paparan banjiran. Penelitian yang bertujuan untuk mengkaji beberapa aspek biologi reproduksi ikan betok di paparan banjiran Lubuk Lampam, Kabupaten Ogan Komering Ilir dilakukan pada bulan Nopember 2012-Oktober 2013. Sampel ikan ditangkap setiap bulanmenggunakan alat tangkap jaring dan bengkirai.Analisis data meliputi sebaran frekuensi ukuran panjang, nisbah kelamin, tingkat kematangan gonad, indeks kematangan gonad, ukuran pertamakali matang gonad, potensi reproduksi dan pola reproduksi. Jumlah sampel ikan betok yang diperoleh sebanyak 540 ekor, terdiri dari 187 ekor ikan jantan dan 353 ekor ikan betina, dengan kisaran panjang ikan betina antara 27-224 mm dan ikan jantan antara 48-243 mm. Rasio kelamin ikan jantan dan betina adalah 0,53 : 1. Tingkat kematangan gonad (TKG) ikan jantan dan betina yang paling banyak ditemui adalah TKG I dengan frekuensi tertinggi pada ukuran 116-132 mm dan 114-129 mmmasing-masing berjumlah 34 dan 33 ekor. Perkembangan tingkat kematangan gonad ikan betok dipengaruhi oleh perubahan tinggimuka air secara musiman. Indek kematangan gonad ikan jantan pada TKGIV berkisar 1,3-15,0%dan ikan betina berkisar antara 1,2 17,1%. Ukuran pertama kali matang gonad ikan betina adalah pada panjang total 160 mm dan ikan jantan pada panjang total 177 mm. Fekunditas ikan betok berkisar antara 224–182.736 butir dengan diameter telur berkisar antara 0,465-1,026 mmdengan pola pemijahan secara sebagian. Climbing perch, Anabas testudineus is a dominant commercial fish inhabit floodplain area of Lubuk Lampam, Ogan Komering Ilir Regency. A study aimed to investigate some aspects of the reproductive biology of climbing perch has been conducted at floodplain of Lubuk Lampam, Ogan Komering Ilir regency from November 2012 to October 2013. Fish sampling was conducted every month using nets and bamboo trap. The data analysis includes lenght frequency distribution, sex ratio, the gonado maturity, gonado somatic index, the size at first maturity, fecundity and reproductive patterns. Climbing perch sample amounted of 540 specimen compose of 187 males and 353 females, with the lenght frequency between 27-224 mm (female) and 48-243 mm (male). Sex ratio of the male and female of the climbing perch was 0,53 : 1. The gonado maturity of male and female are mostly at the first level with the highest frequency between 116-132 mm and 114-129 mm, equivalent to 34 and 33 specimen, respectively. The development of gonado maturity of climbing perch was influenced by seasonally of water level fluctuation. Gonado somatic index of maturity of male and female range 1.3-15.0% and 1.2 -17.1%, respectively. The size at the first maturity of the female was 160 mm lenght and of the male was 177 mm lenght. The fecundity ranges 224 to182,736 eggs with the egg diameter ranges 0.465-1.026 mm and the climbing perch was classified into partially spawner.

Reproductive biology of thin sharpbelly, Toxabramis swinhonis Günther, 1873 in a shallow lake (Biandantang Lake) along the middle reach of the Yangtze River basin (China): implications for fisheries management

2019 ◽  
Vol 55 ◽  
pp. 8
Author(s):  
Xianghong Dong ◽  
Gaël Grenouillet ◽  
Tao Ju ◽  
Tao Xiang ◽  
Zhan Mai ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Reproductive Biology ◽  
Early Stage ◽  
Yangtze River Basin ◽  
Gonadosomatic Index ◽  
Bimodal Distribution ◽  
Spawning Season ◽  
Central China ◽  
High Fecundity ◽  
Wide Range

The reproductive biology of Toxabramis swinhonis, one of the most abundant bycatch species in freshwater fishery in China, was first reported based on 783 specimens collected in Biandantang Lake, central China from October 2016 to September 2017. The overall sex ratio (female/male) was 1.03:1, not significantly different from the expected value 1:1. Nevertheless, sex ratio varied with seasons: 1.32:1 in the early stage of the spawning season (March–April), while 0.46:1 in the later stage (July–August). The monthly succession of the average gonadosomatic index (GSI) and percentages of mature individuals co-indicated that T. swinhonis was a spring-summer (March–August) spawner. Further, the bimodal distribution of the size of eggs from one gravid ovary and histological analysis of mature gonads suggested that T. swinhonis was a multiple spawner with indeterminate fecundity and high degree of spawning asynchronicity. The sizes and ages at first maturity for females and males were 84.47 and 81.86 mm, and 1.62 and 1.56 yr, respectively. The batch fecundity (FB) of this species varied in a wide range from 2006 to 73592 eggs per fish with a mean value of 26487.15 ± 2675.61 (S.E.) eggs and increased with the increasing of the gonad weight (WG), eviscerated weight (WE), total length (LT) and age (A). Overall, T. swinhonis in Biandantang (BDT) Lake is characterized by high fecundity and prolonged spawning season, resulting in easy population explosion. Thus, to remove T. swinhonis moderately or release predator fish discreetly to control its population is proposed considering its reproductive characteristics.

scholarly journals Sexual ratio and floral biology of the dioecious Neea theifera Oerst. (Nyctaginaceae) in a cerrado rupestre of central Brazil

2011 ◽  
Vol 25 (4) ◽  
pp. 785-792 ◽  
Author(s):  
Felipe Wanderley Amorim ◽  
Clesnan Mendes-Rodrigues ◽  
Pietro Kiyoshi Maruyama ◽  
Paulo Eugênio Oliveira
Keyword(s):  
Resource Allocation ◽  
Sex Ratio ◽  
Reproductive Biology ◽  
Reproductive Strategy ◽  
Pollen Viability ◽  
Floral Biology ◽  
Pollinator Limitation ◽  
Dioecious Species ◽  
Male And Female ◽  
Pollination Success

Dioecy is characterized by a complete separation of sexual functions on male and female plants. It has evolved many times in flowering plants and is widespread among distinct Angiosperm families. It is viewed as a reproductive strategy to reduce endogamy, and to promote optimal resource allocation between male and female sexual functions. Neea theifera is a common species in Cerrado, neotropical savannas in Brazil, but information regarding its reproductive biology is still incomplete. In order to investigate how environmental conditions possibly affect this dioecious species, we studied its floral biology, sex ratio and spatial distribution of sexual morphs along a soil-altitudinal gradient. The sex ratio did not significantly deviate from the expected 1:1 ratio. However, flower abundance in the population was significantly biased towards staminate flowers. Female individuals were larger than male individuals and plant size was negatively correlated with altitude, but did not differ between sexual morphs. The population did not show spatial segregation of sexes and male individuals were sexually mature earlier than female ones. Staminate flowers were larger than pistillate flowers and presented high pollen viability. Meliponini bees, small flies and thrips were potential pollinators, but pollination success was very low. Dioecy in N. theifera corroborates many general features of this reproductive strategy, such as woody habit, inconspicuous flowers, pollination by small generalist insects and differential resource allocation between male and female plants. However, reproduction in this species seems to be impaired by pollinator limitation. The results showed that the soil-altitude gradient influenced the growth pattern of the species and may play an important role in its reproductive biology but did not affect dioecy directly.

Sign in / Sign up

Export Citation Format

Share Document