How the body shape changes by the habitat hydrological factors in freshwater benthic fishes; case study on the genera Cobitis (Cobitidae) and Ponticola (Gobiidae)

Benthic fish groups with low mobility are often restricted to a narrow range of a stream course, and their morphological characters tend to be affected substantially by the environmental conditions in their habitat. Due to morphological affectability of fishes by many factors in lotic ecosystems, a landmark-based hypothesis was used to investigate the effects of habitat hydrological conditions on morphological characteristics in freshwater benthic fishes; a case study on the genera Ponticola and Cobitis. A total of 216 gobies and 128 spined loaches specimens were caught from six rivers with different hydrological conditions, along the southern Caspian Sea basin. In discriminant function analysis (DFA), the overall assignment of gobies and loaches into their original groups were 95.7% and 80.5%, respectively. Discriminant analysis for pairwise groups shows a longer snout, shallow body/head, and elongated body for populations living in the large slope channel with faster water velocity versus relatively short snout and deep body/head for those living in small slope channel with slower water velocity. The results confirm the possibility of changes in the morphological characters of the benthic gobies and loaches, which should be considered in taxonomical and biological studies

How the selective breeding in aquaculture programs can change the body shape of cyprinids; a case study on the native Cyprinus carpio and a cultured stock

Decades since restocking program of the vulnerable native Cyprinus carpio in the southern Caspian Sea, the cultured stocks in hatcheries have created new challenge to protect the native population. Releasing the cultured common carp in natural water-bodies caused an uncertainty about originality of the carp broodstocks within the restocking program. To clarify that how the selective breeding with aquaculture purpose could change the body shape with aiming to prepare an identification key for the indigenous and cultured stocks, a landmark based morphological characteristics of these stocks from the Anzali Wetland and a hatchery were analyzed. Univariate analysis of variance of 100 adult specimens collected during the non-reproductive season were observed in 62 morphometric characters out of 78 (P<0.05). Principle component analyze (PCA) of morphometric characteristic showed a high differentiation between these stocks. In morphometric traits, linear discriminate function analysis (DFA), the overall assignments of individuals into their original groups between stocks were 100%. The PCA and DFA showed a morphological segregation of the studied stocks based on the characters head shape, pre-dorsal, pre-pelvic and pre-anal distances, caudal peduncle depth, dorsal fin and ventral fin origins, body depth and caudal fin origin. The results showed stocks represent two distinct morphological forms of C. carpio that had high morphometric differentiation. The results can be useful as baseline information on the native stock for conservational policy. To protect the vulnerable population, using wild native broodstocks in the restocking program is strongly recommended

How did dams affect length-weight and length-length relationships of Capoeta razii (Cyprinidae) in Sefid River, the southern Caspian Sea basin?

Fish populations are affected by dams in terms of morphology, reproduction, migration, growth rate and etc. To examine the hypothesis; how dams can affect the length-weight and length-length relationships in cyprinids, four Capoeta razii segregated populations (by dams) were studied. The length-weight (LWR) and length-length (LLRs) relationships were calculated for three populations from upstream, dam lakes and downstream of Manjil and Tarik dams in Sefid River, in the southern Caspian Sea basin. Also, one independent population from the damming impacts was considered as the control, to examine other possible annual effects on LWR. The b values in the LWR ranged from 2.893 to 3.586 in downstream and dam lakes populations, respectively. The r2 value ranged from 0.966 to 0.988. The averages of recorded length and weight in dam lake population were up to two and six times (respectively) more than the ranges in up and downstream populations. Monthly LWR is presented for the control population. The sex and maturity were found as effective factors on LWR in the control population. No significant differences were observed in LWR by seasons. All LLRs were highly significant (r2> 0.95). This study presents that the dams and the sex and maturity can be considered as effective non-biological and biological factors (respectively) affecting growth patterns as expressed by length and weight relationships in cyprinid (C. razii) populations. The results may be helpful in future fisheries studies and conservation programs

A New Algorithm for the Discrete Shortest Path Problem in a Network Based on Ideal Fuzzy Sets

A shortest path problem is a practical issue in networks for real-world situations. This paper addresses the fuzzy shortest path (FSP) problem to obtain the best fuzzy path among fuzzy paths sets. For this purpose, a new efficient algorithm is introduced based on a new definition of ideal fuzzy sets (IFSs) in order to determine the fuzzy shortest path. Moreover, this algorithm is developed for a fuzzy network problem including three criteria, namely time, cost and quality risk. Several numerical examples are provided and experimental results are then compared against the fuzzy minimum algorithm with reference to the multi-labeling algorithm based on the similarity degree in order to demonstrate the suitability of the proposed algorithm. The computational results and statistical analyses indicate that the proposed algorithm performs well compared to the fuzzy minimum algorithm

Developmental morphology and growth patterns of laboratory-reared giraffe cichlid, Nimbochromis venustus Boulenger, 1908

The giraffe cichlid Nimbochromis venustus Boulenger, 1908 is a well-known species in aquarium trade. The laboratory-reared electric giraffe cichlid was studied in terms of early morphological development and allometric growth pattern from hatching until the juvenile stage i.e.51 dph. Total length increased linearly from hatching until 51 dph, with a high regression coefficient. The yolk sac exhaustion completed throughout 15 days. Significant morphological and morphometric variations occurred before the yolk sac absorption and early juvenile stage by evolving the anterior and posterior body section which improve swimming ability and food capturing. Positive growth coefficient of the body and trunk lengths were occurred after inflexion point coinciding with development of digestive system function. Eye diameter showed negative allometry at the inflexion point of 9.3 mm, continuing with positive growth rate until day 51. Body shape variation in early life history revealed consequent development in anterior and posterior body section in preflexion phase and development of body and trunk length in post flexion phase to support high survival of larvae. The present study emphasizes ontogenic study of different species to interpret biology and ecology of fish in association with evolutionary biology

A mathematical modeling approach for high and new technology-project portfolio selection under uncertain environments

High and new technology-project as a tool to achieve productive forces through scientific and technological knowledge is characterized as knowledge based with high risk and returns. Often conflicting objectives of these projects have complicated their assessment and selection process. This paper offers a novel approach of high technology-project portfolio selection in two main parts. In the first part, a new risk reduction compromise decision-making model is proposed that applies a new approach in determining the weights of experts and in avoiding information loss. The objective function of a new interval type-2 fuzzy sets (IT2Fs) based mathematical model of project portfolio selection is formed by the outcome. To depict model’s applicability, data from case study of high technology-project selection in the literature is used to present the efficacy of the model

Time Prediction Using a Neuro-Fuzzy Model for Projects in the Construction Industry

This paper presents a prediction model based on a new neuro-fuzzy algorithm for estimating time in construction projects. The output of the proposed prediction model, which is employed based on a locally linear neuro-fuzzy (LLNF) model, is useful for assessing a project status at different time horizons. Being trained by a locally linear model tree (LOLIMOT) learning algorithm, the model is intended for use by members of the project team in performing the time control of projects in the construction industry. The present paper addresses the effects of different factors on the project time and schedule by using both fuzzy sets theory (FST) and artificial neural networks (ANNs) in a construction project in Iran. The construction project is investigated to demonstrate the use and capabilities of the proposed model to see how it allows users and experts to actively interact and, consequently, make use of their own experience and knowledge in the estimation process. The proposed model is also compared to the well-known intelligent model (i.e., BPNN) to illustrate its performance in the construction industry

Determining project characteristics and critical path by a new approach based on modified NWRT method and risk assessment under an interval type-2 fuzzy environment

In this paper with respect to the importance of risks in real-world projects and ability of interval type-2 fuzzy sets (IT2FSs) to tackle the uncertainty, a new approach is introduced to consider risks and the correlation among risk factors by subjective judgments of experts on the probability and impact under IT2FSs. Furthermore, a new impact function for considering the correlation among the risk factors are extended under an IT2F environment. Moreover, a new subtraction operator is introduced for the critical path analysis. The node-weighted rooted tree (NWRT) method is modified based on the proposed new operator to avoid producing negative number for characteristics of each activity. Also, in order to cope with the uncertainty of the projects, NWRT method is developed under the IT2FSs. Eventually, to illustrate the validity and capability of the proposed method, two examples from the literature are solved and compared

Solving construction project selection problem by a new uncertain weighting and ranking based on compromise solution with linear assignment approach

Selecting a suitable construction project is a significant issue for contractors to decrease their costs. In real cases, the imprecise and uncertain information lead to decisions made based on vagueness.  Fuzzy sets theory could help decision makers (DMs) to address incomplete information. However, this article develops a new integrated multi-criteria group decision-making model based on compromise solution and linear assignment approaches with interval-valued intuitionistic fuzzy sets (IVIFSs). IVIFSs by presenting a membership and non-membership degree for each candidate based on appraisement criteria could decrease the vagueness of selection decisions. The proposed algorithm involves a new decision process under uncertain conditions to determine the importance of criteria and DMs, separately. In this regard, no subjective or additional information is needed for this process; only the input information required is an alternative assessment matric. In this approach, weights of criteria and DMs are specified based on novel indexes to increase the reliability of obtained results. In this respect, the criteria’ weights are computed regarding entropy concepts. The basis for calculating the weight of each DM is the distance between each DM and an average of the DMs’ community. Furthermore, the linear assignment model is extended to rank the candidates. A case study about the construction project selection problem (CPSP) is illustrated to indicate the application of proposed model