A comparative study of the epidermis of the common carp and the three Indian major carp

A comparative study has been made of the mucogenic epidermis of the common carp, Cyprinus carpio var. communis, and the three Indian major carps, Catla catla, Labeo rohita and Cirrhina mrigala: on the basis of epidermis structural organization, these species are easily differentiated. The epithelial cells in the superficial layer, as in most fishes, show secretory activity, evidenced by positive histochemical reactions, which is high in C. carpio var. communis, moderate in C. catla and low in L. rohita and C. mrigala. The epithelial cells in the underlying two or three layers also give positive reactions, though their intensity is relatively weak. The mucous cells in C. carpio var. communis are distributed in large numbers arranged in several superimposed layers in the outer regions of the epidermis, whereas in C. catla they are fewer in number and are widely separated in the surface layers as well as in the deeper layers of the epidermis; in both species the mucous cells appear rounded, large, and open on the surface by wide pores. In contrast, in L. rohita and C. mrigala the mucous cells are smaller, restricted mainly to the superficial layer, close together in a single row, and open on the surface by narrow pores. The overall density of mucous cells in L. rohita and C. mrigala, as in C. catla, is much lower than in C. carpio var. communis. In the epidermis of C. carpio var. communis there are a large number of mucous cells, and the few club cells are restricted to the deeper layers. In contrast, in the epidermis of the three Indian major carp the overall density of the mucous cells is much lower and the club cells are very numerous. It is suggested that the high density of club cells compensates an overall low density of mucous cells as an adaptation for an effective defence mechanism. Increased mucus production in the epidermis of C. carpio var. communis, as evidenced by a large number of mucous cells in outer regions and high secretory activity of superficial layer epithelial cells, is associated with increased precipitation of mud held in suspension, needed as an adaptation to the species’peculiar bottom-scooping habits. The varied density of the taste buds in the epidermis of the four carp is associated with their feeding habits.     

Isolation and characterization of polymorphic microsatellites in Labeo rohita and their cross‐species amplification in related species

The major Indian carps namely rohu (Labeo rohita), catla (Catla catla), mrigal (Cirrhinus mrigala) and calbasu (Labeo calbasu) are important freshwater species of the Indian subcontinent constituting over 65% of the fish produce. In the present study, isolation of 12 microsatellite loci from rohu has been reported. Cross‐species amplification in related carps and their implication in population genetic studies as well as selective breeding program were discussed.     

Study on impact of habitat degradation on proximate composition and amino acid profile of Indian major carps from different habitats

This investigation is aimed to study an impact of habitat degradation on proximate composition and amino acid (AAs) profile of Catla catla, Labeo rohita and Cirrhinus mrigala collected from polluted, non-polluted area (upstream) and a commercial fish farm. The amino acid profile was estimated by the amino acid analyzer. C. catla collected from the polluted environment had highest lipid, protein and ash contents (12.04?±?0.01, 13.45?±?0.01 and 0.93?±?0.03%, respectively). The high protein content (14.73?±?0.01 and 14.12?±?0. 01%) was recorded in C. catla procured from non-polluted (upstream) wild habitat of River Chenab and controlled commercial fish farm. Farmed fish species showed comparatively higher moisture contents followed by upstream and polluted area fishes. C. mrigala showed significant differences in amino acid and proximate composition collected from a polluted site of the river Chenab. C. catla collected from non-polluted site of the river showed an excellent nutrient profile, followed by L. rohita (wild and farmed) and C. mrigala (polluted area), respectively. All fishes from the polluted areas of the River Chenab indicated a significant decrease in the concentration of some AAs when compared to farmed and wild (upstream) major carps. Omitting of some important AAs was also observed in the meat of fish harvested from polluted habitat of this river. C. mrigala and L. rohita exhibited a significant increase in the concentration of some of non-essential amino acids such as cysteine in their meat. The results indicated that wild fish (upstream) and farmed fish species had highest protein contents and amino acid profile and hence appeared to be the best for human consumption. The proximate composition and AAs profiles of fish harvested from the polluted area of the river clearly indicated that efforts shall be made for the restoration of habitat to continue the requirement of high quality fish meat at a low cost to the human population.     

Consumption of zooplanktonic organisms by Astyanax fasciatus Cuvier, 1819 (Osteichthyes,Characidae) in Lobo (Broa) reservoir,São Carlos,SP, Brazil

The consumption of zooplanktonic organisms by young and adult fish of Astyanax fasciatus in Lobo Reservoir was studied from October 1978 to September 1979 by analysing the abundance of zooplankton in the gut of fishes and relating it to the variation of the zooplankton community in the lake. To analyse the diet the following methods were used: numeric frequency of occurrence, and frequency rate. Astyanax fasciatus showed a large spectrum of feeding. The young stage feeds mainly on zooplankton and macroinvertebrates (insect larvae) but the adults also consume algae and detritus. Even in relation to the zooplankton the young stage showed a food preference different from that of the adults, selecting copepods over cladocerans, while the adults consumed more cladocerans.     

Comparative and evolutionary analysis of mitochondrial genes in Indian major carps

Direct sequencing of mitochondrial DNA regions such as cytochrome b, ATPase 6/8 and control region was performed to study comparative and evolutionary status of the three mitochondrial genes in Labeo rohita, Catla catla and Cirrhinus mrigala. DNA sequence alignment among species using specific software revealed comparative rates of divergence with considerably faster and more heterogeneous substitution rate for control region as compared to cytochrome b and ATPase 6/8. Despite the relatively high variability of control region, the overall levels of sequence divergence were low in coding regions. Two protein coding genes and the control region with varying degree of sequence divergence established two distinct groups which are genetically distant from each other exhibiting identical phylogenetic structure in IMCs. Closest relationship was between Labeo rohita and Catla catla indicating that they might have diverged from a common ancestral stock in genealogical lineage whereas Cirrhinus mrigala showed greater divergence with all the three DNA regions studied. Findings of this study will help to understand evolution of mitochondrial DNA genes in carps and facilitate future investigations on phylogeographic structure of Indian carps.     

Performance of different fish species for controlling weeds in rainfed lowland rice field

A field experiment was conducted during wet season to evaluate the performance of different fish species for biocontrol of weeds in rainfed waterlogged rice fields with fingerlings of three exotic carps – grass carp, Ctenopharyngodon idella (Val.) (Cyprinidae, Cypriniformes), silver barb, Puntius gonionotus (Bleeker) (Cyprinidae, Cypriniformes) and common carp, Cyprinus carpio (L.) (Cyprinidae, Cypriniformes) – and three Indian major carps – rohu, Labeo rohita (Ham.) (Cyprinidae, Cypriniformes), catla, Catla catla (Ham.) (Cyprinidae, Cypriniformes), mrigal, Cirrhinus mrigala (Ham.) (Cyprinidae, Cypriniformes). A total of 13 major weeds under the categories of grassy, sedges, broadleaf and aquatic weeds were observed in the rice fields. Grass carp reduced maximum weed biomass (weed control efficiency [WCE] 63% at 60 days after transplanting [DAT] and 62% at 100 DAT) followed by silver barb and common carp. Among the Indian carps, only rohu was effective in control of weeds (WCE, 23% at 60 DAT). The grain yield of rice (variety Varshadhan) slightly increased (4.2–4.5 t/ha), but straw yield was significantly higher (10.2–10.7 t/ha) under rice-fish farming. Fish yield was significantly higher in exotic carps (270–288 kg/ha/90days) due to higher specific growth rates (1.8–2% body weight/day). The study indicated that exotic carps (grass carp, silver barb and common carp in order) were more effective than Indian carps for control of weed in rainfed lowland rice fields and among the Indian carps, rohu showed potential for weed control.     

Non-specific immune responses in juveniles of Indian major carps

The non‐specific immune parameters are useful to determine the health status of fish and to evaluate the immunomodulatory substances for fish farming as markers of pollution and disease resistance. Some of the important parameters, viz. superoxide production by neutrophils through nitroblue tetrazolium (NBT) assay; haemagglutination (HA), haemolysin (HLY) and bacterial agglutination titres; myeloperoxidase (MPO), and lysozyme activities, and alternative complement levels in serum of the juveniles of three Indian major carp species (Cirrhinus mrigala, Catla catla and Labeo rohita) were measured to establish their physiological normal range. A wide variation among the individuals within a species in the ranges of the most of the immune parameters was recorded. Significantly higher levels in the mean values of HA, HLY, bacterial agglutination titres; superoxide production by neutrophils in nitroblue tetrazolium assay; serum MPO and lysozyme activities, i.e. 371.20, 4.60, 18.80, 0.40, 0.62 and 6.55 μg ml^?1, respectively, were obtained in L. rohita except a much lower alternative haemolytic complement activity (29.06 units ml^?1) compared with the other two species. In most of the parameters, L. rohita showed the highest value, possibly indicating its more natural resistance compared with the other two species.     

Sucrose metabolism in green algae I. The presence of sucrose synthetase and sucrose phosphate synthetase

Summary The presence of sucrose synthetase and sucrose phosphate synthetase has been demonstrated in two species of green algae:Chlorella vulgaris andScenedesmus obliquus. Partial purification from crude extracts allowed the determination of the kinetic constants of algae enzymes. They are very similar to the ones reported for enzymes from higher plants.Dedicated toLuis F. Leloir on his seventieth birthday.     

Length–weight relationships of four Cyprinid species in India

Length–weight relationships are reported for four Indian carps. The length–weight relationship was W = 0.01123L^3.355 for Cirrhinus mrigala, W = 0.07354L^3.299 for Catla catla, W = 0.04066L^3.313 for Labeo rohita and W = 0.11489L^2.732 for Labeo fimbriatus. LWR estimates for C. mrigala and L. fimbriatus had not been previously reported in FishBase.     

Comparison of plankton intake by Indian carp fingerlings under different feeding conditions

The influence of different culture systems on the amount of plankton consumed by fingerlings of three carp species (Labeo rohita, Catla catla and Cirrhinus mrigala) was examined in outdoor culture tanks during a 90 day growing period. The fish were raised under two basically different feeding conditions: (a) fed with allochthonous live plankton; (b) fed with plankton grown autochthonously in the fish growing tanks fertilized with manures. Both feeding regimes were compared with control groups. It was found that the plankton intake for carp held in the live food system was significantly higher than with the manured and control systems. Related to maximum intake, maximum abundance of plankton in the live food system was a consequence of improved water quality expressed in terms of lower values of BOD and COD and higher values of DO and pH; this was conducive to fast reproduction of some of the zooplankton which constituted the major food items for the test carp, as well as to the regular exogenous introduction of live plankton. The ingestion of plankton was found to be related to carp body weight raised to the power b. The exponent b ranged from 0.29 to 0.93 during the 90-day growing period.     

Natural diet of herbivorous zooplankton in Lake Xolotlán (Managua)

The natural diet of herbivorous zooplankton was analyzed for a better understanding of the trophic relationships in Lake Xolotlán (Managua). Gut content of the most common zooplankton species (Arctodiaptomus dorsalis, Moina micrura andDiaphanosoma fluviatile) were analyzed. The quality and the relative abundance of ingested algae was studied. The most consumed algae during the dry season (February) wereCyclotella, Oocystis andLyngbya, and during the rainy season (November)Cyclotella, Oocystis andChroococcus. The kind of food ingested byA. dorsalis andM. micrura was similar in both periods. There was no similarity with the diet ofD. fluviatile. During the dry season, when algal biomass in the lake was high,A. dorsalis andM. micrura ingested a higher proportion of diatoms. During the rainy season, when food was scarce, the diet was more diverse and bluegreen algae (Chroococcus) were ingested in a larger proportion.Diaphanosoma fluviatile ingested predominantly tiny particles (bacteria and detritus) and algal food consisted mainly of green algae (Oocystis) and probably (not studied) nanoplanktonic algae. The results were consistent with those obtained in other lakes, indicating the importance of diatoms and green algae for zooplankton nutrition.     

Characterization of IgM of Indian major carps and their cross-reactivity with anti-fish IgM antibodies

Indian major carps (IMC), rohu (Labeo rohita), catla (Catla catla) and mrigal (Cirrhinus mrigala) were immunized with bovine serum albumin and the serum immunoglobulin M (IgM) was purified by affinity chromatography. The heavy and light chain of IgM of all the three species of IMC were about 88 and 26 kDa, respectively. Anti-fish IgM antibody against all the three species were raised in mice and the reaction of anti-fish IgM antibodies with IgM of all the three species of IMC were studied by Western blot. The anti-fish IgM antibodies reacted strongly with the heavy chain of the same species against which it was raised while the reactions with the heavy chain of other species were milder indicating some degree of epitope sharing among the heavy chains of IgM of IMCs. However, there was no cross-reaction with the light chain of any of the IgM.     

The effects of diet mixing on consumer fitness: macroalgae, epiphytes, and animal matter as food for marine amphipods

Herbivores are thought to achieve adequate nutrition by consuming numerous species of plants or by occasionally consuming animal tissue. Although active selection of diverse foods is common in nature, the relationship between diet mixing and consumer fitness is poorly understood, especially in marine environments. We studied the fitness-based consequences of dietary mixing in the sympatric amphipods Ampithoe marcuzzii, A. valida, Cymadusa compta, and Gammarus mucronatus by measuring survivorship, growth, and fecundity of these amphipods when they were offered single species of algae, a single animal food, a mixture of algal species, or a combination of algae and animal matter. For the more sedentary, tube-building amphipods A. marcuzzii, A. valida, and C. compta, fitness on mixed algal diets was matched by fitness on at least one of the monospecific algal diets, suggesting that they could benefit from preferential feeding on those algae in the field. The more mobile amphipod, G. mucronatus, survived and grew similarly on the mixed diets and on the filamentous brown alga Ectocarpus siliculosus. However, its fecundity was significantly higher when feeding on the algal and animal mixture than on Ectocarpus alone. Additionally, for G. mucronatus, fitness on mixed algae, mixed algae plus animal matter, and animal matter alone was equivalent, although female growth (but not gonad production) was slightly lower on animal matter alone than on the mixed algae combined with animal food. Thus the more mobile amphipod, G. mucronatus, was the only species able to perform well on animal food alone. In contrast, A. valida and C. compta experienced large negative effects when limited to consuming animal matter alone. For these two species, combining algae and animal matter did not enhance fitness over combining only algae. Fitness effects of specific algal diets showed some general similarities, but also considerable variance among the amphipods. For example, E. siliculosus was generally better food than other algae for all four amphipods, whereas Sargassum filipendula was generally poor. However, A. marcuzzii did not suffer negative effects of consuming only Sargassum. The red alga Polysiphonia sp. and the green alga Enteromorpha flexuosa decreased fitness in A. marcuzzii, C. compta, and G. mucronatus, but not A. valida, and the negative effects of Polysiphonia were considerably larger for A. marcuzzii than for the other amphipods. Our data show that nutritional requirements, even among related species (e.g., A. marcuzzii and A. valida), can be dramatically different. Diet mixing may benefit more mobile consumers like Gammarus that are better able to search for different foods, and may be less important for more sedentary herbivores like Ampithoe and Cymadusa that consume, and live in close association with, individual host plants. Received: 14 September 1998 / Accepted: 22 October 1999     

A note on the potential applicability of malachite green oxalate in combating fish-mycoses

In the present investigations the potential fungicidal ability of malachite green oxalate has been tested in vitro on four fish-pathogenic isolates of Saprolegniaceous fungi viz.,Saprolegnia ferax (Gruith) Thuret,Achlya flagellata Coker,Aphanomyces laevis De Bary andIsoachlya anisospora var.indica Saxena and Bhargava and the lowest concentration having fungicidal ability has been found to be 0.5 ppm. Tolerance tests have also been conducted usingPuntius sophore, Colisa lalia, Anabas testudineus andCatla catla as test fishes. Also the applicability of the lowest fungicidal concentration of this chemical (i.e. 0.5 ppm) in sustained culturing of the adult individuals ofCatla catla, a major food fish, against the mycotic infection, has been tested.     

Marine macroalgae as foods for fishes: an evaluation of potential food quality

Synopsis A revitalized view of feeding by herbivorous marine fishes is sought through two questions. First, What characteristics of major taxa of algae identify them as predictably high or low quality foods? Second, are marine algae valuable foods for fishes which do not mechanically disrupt cell walls and do not harbor specialized enzymes or microbes capable of lysing cell walls? Energy, ash and nutrient content of 16 species of marine algae were employed to assess food quality of fleshy red, green, brown and calcareous red algae. On the basis of ash, calories, total protein and total lipid content, fleshy algae should be superior to calcareous algae as foods for fishes; in addition, green algae should be superior to brown algae and brown algae superior to red algae. When the probable digestibility of storage and extracellular carbohydrates is considered, green and red algae are predicted superior to brown algae as food. Two species of damselfishes (Pomacentridae) from the Gulf of California,Eupomacentrus rectifraenum andMicrospathodon dorsalis, eat red and green algae and ignore brown and calcareous algae. They feed, therefore, in a fashion consistent with predictions based only on algal chemistry. These fishes absorb at least 20–24% of the biomass, 57–67% of the protein, 46–56% of the lipid and 37–44% of the carbohydrate contained in algae eaten in the wild. Since these damselfishes do not masticate their food, it appears that herbivorous fishes can digest major fractions of algal nutrients without mechanical destruction of algal cells.     

Karyotype studies in seven species of cyprinidae

The present report embodies karyotype studies of seven Indian cyprinids. Of these, the karyotypes of five species possess chromosomes all of which are acrocentric. These areLabeo calbasu (Ham.) 2n=54,Puntius sophore (Ham.),P. conchonius Ham.,P. stigma (Ham.) 2n=50 andChela bacaila (Ham.) 2n=52. The karyotype ofCrossocheilus latius punjabensis Mukerji has 48 chromosomes, 12 of which are metacentric (2n=12m+36r's). InAmblypharyngodon mola (Ham.), 52 chromosomes form the diploid set which include 8 metacentrics. In none of the seven species morphologically distinguishable sex chromosomes were found.Literature on cyprinid karyotypes has been reviewed in order to understand in how far the cytological characters are in agreement with the classification based on morphological studies. The validity ofMatthey's notion of nombre fondamental to establish kinship between cytologically known cyprinid species has also been discussed.     

A discussion of the classesChlamydophyceae andChlorophyceae and their subordinate taxa

The diagnostic characters alleged byEttl (1981) andEttl &Komarek (1982) to distinguish the ClassesChlamydophyceae andChlorophyceae are discussed. The recognition of these classes ignores ultrastructural evidence of the close phylogenetic relationships of their members and produces an artificial redistribution of orders, families, and genera that can only lead to confusion in the taxonomy of the green algae. Suggestions for a more natural classification are made.     

Comparative studies on the regulation of DAHP synthetase activity in blue-green and green algae

Summary Regulation of DAHP synthetase activity was investigated in autotrophically grown blue-green and green algae. Members of the class of blue-green algae possess an enzyme, the activity of which is regulated by l-tyrosine and l-phenylalanine, whereby l-tyrosine is effective in 100 fold lower concentrations. DAHP synthetases of two organisms, Anabaena and Anacystis, were shown to belong to the V-type of allosteric enzymes.In contrast to the DAHP synthetase of blue-green algae regulation of this enzyme could not be demonstrated in two green algae, Ankistrodesmus and Maesotaenium. However, Euglena gracilis, both under conditions of mixotrophic and autotrophic growth, exhibits very effective regulation of this key enzyme; again, the inhibitors are tyrosine and phenylalanine. DAHP synthetase activity of Euglena has been purified about 40 fold; during this enrichment no separation of the enzyme activity inhibited by tyrosine and that by phenylalanine could be observed.     

Three new green coccoid zoospore-producing algae from the Great Smoky Mountains National Park,Tennessee, U.S.A.

Three new coccoid zoospore-producing green algae includingAxilococcus clingmanii gen. & spec. nov.,Lautosphaeria monsfumosa gen. & spec. nov., andDictylochloris pulchra spec. nova (Chlorococcales, Chlorophyceae) are described.Dedicated to Prof. DrLothar Geitler on the occasion of his 90th birthday.     

Hemp (Marijuana) reverted Copper-induced toxic effects on the essential fatty acid profile of Labeo rohita and Cirrhinus mrigala

Heavy metals pollution affects the nutritive value of fish. This study examined if the inclusion of dietary hempseed (HS) and hempseed oil (HO) in the diet of the fish could revert the copper-induced toxic effects on muscle fatty acid profile of rohu (Labeo rohita) and mrigal (Cirrhinus mrigala). Fingerlings of both species were exposed to a sub-lethal concentration of copper i.e., 20% of LC₅₀ (1.34 ppm for rohu and 1.52 ppm for mrigal) for 96 h for 30 days. Following exposure, fish were maintained on graded levels of HO (1, 2 and 3%) or on HS (5, 10 and 15%) for 50 days. Copper exposure showed a significant effect on the fatty acid composition of both species; increased their saturated (SFA) to unsaturated (USFA) and altered their omega-3/omega-6 (ω-3/ω-6) ratios. However, feeding graded levels of hempseed products reverted the toxic effects of copper on the fatty acid profile of both the species, significantly increased muscle total fatty acid contents, improved ω-3/ω-6 ratios, and decreased SFA / USFA ratio in % inclusion dependent manner. Furthermore, hempseed product showed a species-specific effect on USFA. The ω-3/ω-6 ratios decreased in the muscle of C. mrigala whereas an increasing trend with an increase in hempseed product % inclusion was observed in L. rohita. Moreover, HS showed a higher impact on both species as compared to HO. With the findings of this study, hempseed product could be recommended as a feed ingredient for enhancing the essential fatty acid contents of fish which in turn can have a good impact on consumer health.