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1.
Length–weight relationship (LWR) was estimated for 12 elasmobranch species; five shark species, four species of rays and three species of guitar fishes from north‐eastern Arabian Sea, India. Five major landing centres of Maharashtra were selected; Satpati (Lat. 19°43′15″N, Long. 72°42′00″E), Naigaon (Lat. 19°19′32″N, Long. 72°48′54″E), Versova (Lat. 19°08′33″N, Long. 72°48′11″E), New ferry Wharf (Lat. 18°57′29″N Long. 72°51′01″E) and Sassoon dock (Lat. 18°54′42″N, Long. 72°49′33″E). Samples were collected fortnightly during August 2016 to October 2017 from various gears; drift gill nets (Hung length 114–143 m and #100–270 mm) off Satpati coast at 35–50 m depth, dol nets (length 50–65 m and cod end # 30–69 mm) in Naigaon at 38–50 m depth and trawl (length 33–72 m and cod end # 17–32 mm) in Versova, New ferry Wharf and Sassoon dock operated at 20–50 m depth. Multiday fishing was carried out with 2–3 fishing trips in a month, each trip with duration of 7–13 days. Soaking time of gill net and dol net varied from 4 to 8 hr while each trawl haul lasted for 3–4 hr. Length–weight/Disc‐width‐weight relationship showed good fit with r2 values varying from 0.818 to 0.999. In addition to information on LWR, new maximum size for three species of elasmobranchs is reported in this paper.  相似文献   

2.
Parameters of the length‐weight relationship (LWR) were estimated for seven fish species from Amazonian Equatorial coast of Maranhão, Brazil. Samplings were carried out in three sample points of the lower stretch of the Itapecuru River (2°57'6.2"S and 44°14'26.5"W; 3°0'33.0"S and 44°15'54.7"W; 3°3'42.9"S and 44°15'1"W). The specimens were caught quarterly from June 2012 to August 2014 using monofilament gillnets (10, 20, 30, 40, 50, 60, 70 and 80 mm between knots) from 10 m to 30 m long and 4 m to 6 m high. This study provides the LWR parameters for Schizodon dissimilis, Curimata macrops, Prochilodus lacustris, Geophagus surinamensis, Hassar affinis, Platydoras brachylecis and Hypostomus plecostomus.  相似文献   

3.
In this study the diet of Stellifer rastrifer and S. brasiliensis were analysed in order to assess the role of resource partitioning between these congeneric, sympatric and abundant species along the coasts of Paraná (25 °55′28″S; 48 °33′35″W) and Santa Catarina (26 °25′55″S; 48 °34′46″W), in southern Brazil. The stomach contents of 240 S. rastrifer specimens (52–195 mm total length) and 167 S. brasiliensis (60–182 mm total length) collected by trawl boat in March of 2006, were analysed to assess the influence of sites, day and night periods as well as the size class in their diet composition. Although crustaceans have been the main resources of both species, S. rastrifer consumed pelagic and epibenthic items, whereas S. brasiliensis also used benthic resources. Results of permanova analysis provided significant evidence for food resource partitioning and confirm the role of feeding changes in the function of morphology (species, P = 0.001), behaviour (day and night, P = 0.024), and ontogeny (size classes, P = 0.001), strategies to reduce competition and to maintain the coexistence of these syntopic species.  相似文献   

4.
The paper investigates the length‐weight relationship of three cichlids species for the southwestern Amazon, Acre state. The individuals were collected at five sites during one year among august/2016 and june/2017 in Quinoá stream (10°06′03.33″S/67°40′11.50″W). The individuals were collected using: seine net, 6 m length, 2.25 high, and mesh size 5 mm, two dip nets, 5 mm mesh, 30 cm width, and 50 cm in length and two sieve with 5 mm mesh, 50 cm width, and 80 cm in length. The results show that one species presented positive allometric growth (Aequidens tetramerus) and the others negative allometric growth (Apistogramma acrensis and Crenicichla semicincta).  相似文献   

5.
Length‐weight and length‐length relationships were investigated for 13 freshwater fish species from the lower Jinsha River, southwest China (from 101°32′49.63″E; 26°35′38.27″N to 104°37′48.14″E; 28°45′59.55″N). Fish were sampled from five sites during 2014 and 2016, using trap‐nets, gillnets (major mesh size: 2–6 cm), longline and electrofishing. Length‐weight relationships for six and length‐length relationships for 12 species are the first report to FishBase, respectively. Moreover, new maximum length for 11 species are also presented to FishBase in this study. All regressions were highly significant (< .001), with the coefficient of determination r> .950. These information will be helpful for management and conservation in local fishes and fisheries.  相似文献   

6.
Length–weight relationships (LWRs) of three fish species: Scomberomorus commerson, Alepes vari, and A. kleinii were estimated from Kerala waters, south‐west coast of India. Fish were captured between June 2016 and June 2017 by various gears such as ring seine (8–26 mm mesh size), trawl (30–40 mm cod end mesh size), hook and line (hook number VI–XII), smaller mesh sized drift gill net (26–90 mm) and larger one (120–170 mm) for bigger size fishes. Fish were collected on weekly basis from Cochin Fisheries Harbour (Lat. 09°56′327″N, Long. 76°15′764″E), Munambam Fisheries Harbour (Lat. 10°10′965″N, Long. 76°10′258″E), Kalamukku (Lat. 09°59′924″N, Long. 76°14′564″E) and Chellanam (Lat. 09°47′950″N, Long. 76°16′551″E). All LWRs were significant with r2 values ranged from 0.944 to 0.996 and b values ranged from 2.722 to 3.021 (< .001). In addition, this study provides the information on LWRs and new maximum size for Alepes vari and A. kleinii.  相似文献   

7.
This investigation prepares the length–weight relationships (LWRs) of two fish species, including Alburnoides nicolausi (Bogutskaya & Coad, 2009) and Alburnus zagrosensis (Coad, 2009) from Houzian River (latitude 33°22′15.20″ to 33°21′31.57″N; longitude 49°44′39.66″ to 49°44′17.67″E), Lorestan province, Iran. Fish specimens were collected monthly using seine net with 5 mm (Stretched) mesh size between April to September 2017. The LWRs for fish species were W = 0.0059L3.405 (male) and W = 0.0053L3.494 (female) for A. nicolausi, W = 0.0035L3.341 (male) and W = 0.003L3.387 (female) for A. zagrosensis, respectively. The highest value of r2 was .931 for male of A. zagrosensis and lowest value was .964 for male of A. nicolausi.  相似文献   

8.
Adaptive strategies of desmids in two tropical monomictic lakes were studied in relation to morphometric differences. The study aimed at evaluating desmids' strategies during inter-annual succession patterns in two tropical lakes (Dom Helvécio and Carioca) in southeast Brazil. From monthly samples of freshwater algae collected during five consecutive years (2002–2006) from the two lakes, the desmids were classified according to size, life form, and life strategies (competitive, stress tolerant, and ruderal). Our results indicated that Lake Carioca (19º45′20″S, 42º37′12″W), a small, shallow, turbid, and mesotrophic system showed dominance of invasive/opportunistic taxa (C) and R-strategists (Staurastrum species <20 μm), whereas Lake Dom Helvécio (19º45′–19º48′45″S, 42º33′45″W), a large, deep, and clear system was dominated by ruderal (R) species (Closterium aciculare and Pleurotaenium trabecula >50 μm) and tolerant to stress (S) species (Staurastrum and Staurodesmus species >20 μm). A significant number of desmids from the lakes had low MLD (≤20 μm), low volume (<103), and high SV?1 ratio (>1). Consequently, C-strategist species were abundant and formed a group having great adaptive value in the lakes, with higher resilience and capacity to change composition after the turnover period. Stratification stability and atelomixis were the main driving forces to sustain high desmid biomass in these two lakes, despite the greater macrophyte richness and great water column depth at Lake Dom Helvécio and the main factor influencing richness and contribution of complex forms.  相似文献   

9.
Results of paleoparasitological examination of rodent coprolites collected from archaeological and paleontological sites from Patagonia, Argentina, are present. Each coprolite was processed, rehydrated, homogenized, spontaneously sedimented and examined using light microscope. Coprolites and eggs were described, measured and photographed, and were compared with current faeces of Lagidium viscacia. Eggs with morphological features, attributed to an anoplocephalid cestode were found in samples collected from Cueva Huenul 1 (36°56′45″S, 69°47′32″W, Neuquén Province, Holocene) and Los Altares Profile (43º53′35″S, 68º23′21″W, Chubut Province, Late Holocene). These are the first findings of this anoplocephalid from faecal material from patagonic rodents.  相似文献   

10.
Length‐weight relationships (LWRs) for four fish species from the River Ganga (India) is presented. Sampling was conducted in the lower stretch of the river (Buxar: 25°33′43.90″N and 83°56′3.10″E to Freserganj: 21°35′40.58″N and 88°15′28.92″E) on tri‐monthly basis from September 2016 to December 2017. Specimens were caught in gill nets (mesh, 18–68 mm), cast nets (mesh, 12–14 mm), seine nets (mesh, 12–14 mm) and various traditional traps those were put over night and lifted in early morning. Total length and wet body weight of fish were measured to the nearest 0.1 cm and 0.01 g by a digital caliper and electronic balance respectively. From LWRs, the estimated b values were found to be 2.88 (Pisodonophis boro) to 3.17 (Gagata sexualis) whereas a value ranged from 0.001 (Pisodonophis boro) to 0.009 (Botia lohachata). As per FishBase, the species Gagata sexualis and Botia lohachata had new TLmax reported for LWR estimation.  相似文献   

11.
Length‐weight relationships (LWRs) for three fish species from the River Ganga (India) is presented. Sampling was conducted from the lower stretch of the River Ganga (Patna: 25°36′51.66″N & 85°12′7.02″E to Freserganj: 21°35′40.58″N & 88°15′28.92″E) during April, June and September and December of 2017. Specimens were caught using gill nets (18 nos.; mesh 18–32 mm), and bag nets (3 nos.; mesh 14–22 mm). The values a and b from LWRs ‐were found to be 0.007 and 2.977 for Eutropiichthys murius; 0.003 and 3.001 for Coilia reynaldi; 0.009 and 3.010 for Johnius gangeticus.  相似文献   

12.
In the coastal pine forests (Pinus pinea and Pinus pinaster) of Ravenna (Italy) along the Adriatic coast, many pine trees are stressed or dying. In this paper we present ground elevation, depth to watertable, salinity of groundwater and vegetation species richness data within one of the coastal pine forests and some wetlands north of the Bevano River between LAT. 44°23′10″ and LAT. 44°20′21″ and between LONG. 12°17′25″ and LONG. 12°19′33″. The data are presented areally and along a 50 m long transect perpendicular to the coast to study the cause of distress in the pine forest and in different water pools within the wetlands. The findings were compared to published values of tolerance to salinity for 39 plant species typical of the area and incorporated into a web application to help nature managers in assessing or adjusting water salinity in relation to the vegetation species present. The pine trees are relatively tolerant to salinity (up to 12 g/l) but cannot survive a shallow watertable. On the other hand, species richness or biodiversity in this area is promoted by a shallow watertable and low salinity.  相似文献   

13.
Present study provides length–weight relationships (LWRs) and length–length relationships (LLRs) of eight fish species from river Ganga, India. Specimens were sampled from gill nets (mesh, 22–120 mm), cast nets (mesh, 12–14 mm), and seine nets (mesh, 12 mm) on quarterly basis from September 2016 to September 2017 within the river stretch from Buxar (25°33′43.90″N and 83°56′3.10″E) to Freserganj (21°35′40.58″N and 88°15′28.92″E). The b value ranged from 2.86 (Otolithoides pama) to 3.08 (Polynemus paradiseus), whereas a value ranged from 0.004 (P. paradiseus) to 0.016 (Rita rita). Both relationships (LWRs and LLRs) were found to be highly correlated (p < .001). This study provides first report on LWR for Amblyceps mangois and Osteobrama cotio, whereas new maximum length recorded for Macrognathus pancalus. Furthermore, the estimate of R. rita should be considered as tentative because of the limited size range in the study.  相似文献   

14.
Length‐weight relationships (LWRs) were determined for nine fish species occurring in the Three Gorges Reservoir(28°56′–31°44′N, 106°14′–111°28′E). Fish were collected using gill nets, including two of 1.0 m depth, 100 m long, and mesh size of 0.5 cm; two of 1.0 m deepth, 150 m long, and mesh size of 2.0 cm; and one of 1.5 m deepth, 100 m long, and mesh size of 6.0 cm. Gill nets were set over night including different habitats (riffles and pools, vegetated and non vegetated zones) from seven sites seasonally from January 2014 to January 2018. The first LWR reference for Jinshaia abbreviata (Günther, 1892), and Triplophysa tanggulaensis (Zhu, 1982) and new maximum lengths for other seven species are provided when comparing with records given in the international electronic databank FishBase (Froese & Pauly, FishBase. World Wide Web electronic publication, 2018).  相似文献   

15.
Length–weight (LWR) and length–length (LLR) relationships were estimated for specimens of two gobiid species collected from the Anzali Wetland and its related streams in the southern Caspian Sea basin, in August 2017. These represent the first reports of LWR and LLR data for Rhinogobius cf. similis Gill, 1859 (37°28′13″N, 49°20′33″E; 50 individuals) and Proterorhinus nasalis (De Filippi, 1863) (36°54′10.89″N, 53°48′48.33″E; 30 individuals) from the Wetland. A new maximum length is reported for P. nasalis. The length–weight parameter b for these species ranged a minimum of 2.99 for Rhinogobius cf. similis to a maximum of 3.04 for P. nasalis with regression coefficients (r2) ranging from .95 to .97. All LLRs were highly significant (r2>.96).  相似文献   

16.
我国东北地区发现姬鼩鼱分布   总被引:1,自引:0,他引:1  
2014年在黑龙江省横道河子地区(44°48′44″N,129°02′04″E,海拔约740 m)采集到1只鼩鼱(标本编号为CH5)。2015年在内蒙古自治区达赉湖地区(48°37′20″N,117°53′17″E,海拔约720 m)采集2只鼩鼱(标本编号为DE7和DE12)。这些新获标本经鉴定为姬鼩鼱(Sorex minutissimus)。《小鼩鼱(食虫目:鼩鼱科)辽宁省新纪录》文中的标本(080910,090920)经重新鉴定也为姬鼩鼱。利用mt DNA的Cyt b基因全序列构建系统进化树,结果揭示,小鼩鼱聚为一支,姬鼩鼱聚为另一支,新获标本(CH5、DE7、DE12)和待厘定标本(080910、090920)都聚在姬鼩鼱一支,进一步支持形态学鉴定结果。2015年采集的姬鼩鼱为内蒙古自治区新纪录,而《小鼩鼱(食虫目:鼩鼱科)辽宁省新纪录》文中的小鼩鼱(Sorex minutus)(标本号:080910,090920)更正为辽宁省姬鼩鼱新纪录。  相似文献   

17.
The Japanese fringed sculpin Porocottus japonicus Schmidt has been found in the Rynda (44°48′03″ N, 136°23′24″ E) and Vladimira (43°52′36″ N, 135°29′30″ E) (Sea of Japan, Primorskii krai) bays for the first time. This species was formerly known only from the northern Tatar Strait and Aniva Bay. In Primorskii krai, P. japonicus inhabits macrophyte beds in shallow sublittoral waters. It reaches a length of 112 mm during its lifespan of approximately 4 years. Spawning occurs in the winter. The species preys predominantly on polychaetes (82.3% of the food weight).  相似文献   

18.
Antonie van Leeuwenhoek - Two novel Gram-negative bacterial strains BT190T and BT191 were isolated from soil collected in Uijeongbu city (37°44′55″N, 127°02′20″E),...  相似文献   

19.
Length–weight relationships were determined for three fish species (Cynoglossus macrolepidotus (Bleeker, 1851), Liparis tanakae (Gilbert & Burke, 1912), Zoarces elongatus (Kner, 1868)) from Bohai Sea (38°38′–40°28′N; 119°42′–121°10′E), China. Fish specimens were sampled monthly between May 1982 to May 1983 using pair bottom trawlers (150.5 × 96.5 m, mesh size: 30–200 mm) with a cod end (mesh size: 30 mm), which were towed at a ship's speed of two knots for 1 hr at a maximum depth of about 80 m. Relationships between length and weight were fitted very well for all species (all R2 > .90).  相似文献   

20.
Length–weight relationships (LWR) were estimated for four fish species caught in the Tucuruí Lake Conservation Units Mosaic (03°48’15.7”S, 049°033’033,3”W; 04°13’18.2”S, 049°041’038.5”W and 04°17’57.1”S, 049°026’006.3”W). The samples were collected trimonthly between March 2013 and December 2014, using seven different gill nets (20 × 3.0 m; mesh size: 4, 6, 8, 10, 12, 14, and 16 mm between opposing knots) spending for twelve hours per day.  相似文献   

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