Loading [MathJax]/jax/output/SVG/jax.js

Open-access Phenotypic variation of Thenus spp. (Decapoda, Scyllaridae) in the waters of southern Thailand and Malaysia using multivariate morphometric analysis

ABSTRACT

Thenus spp. are slipper lobsters which are commercially significant as a food source with good aquaculture potential. This study focuses on collecting population information on Thenus orientalis and Thenus indicus from selected sites in southern Thailand and Malaysia to inform sustainable fisheries management about the resources. Twenty-five size-adjusted morphometric measurements were analyzed using canonical discriminant function and dendrogram cluster analyses to examine patterns of phenotypic variation between sites. Significant phenotypic variation with distinct centroids and minimal overlapping cases were observed among four sites of T. orientalis (p < 0.05), as well as cluster analysis groupings occurring as in (i) Kota Kinabalu and Kudat, in Sabah, Malaysia; (ii) Pattani; and (iii) Nakhon Si Thammarat, in Thailand, which were best discriminated by the width of the third pereiopod merus, the sixth abdomen segment, and the carapace posterior margin. Similar morphometric data between Kota Kinabalu and Kudat suggests a subpopulation of T. orientalis occurring in Sabah waters. Significant phenotypic variation was also detected between six sites of T. indicus (p < 0.05), with close centroids and overlapping cases forming three groups: (i) Ranong and Nakhon Si Thammarat; (ii) Kota Kinabalu, Tanjung Sedili, and Kuala Terengganu; and (iii) Pattani, best described by the widths of the second antenna and the first pereiopod merus, in addition to the length of the sixth abdomen segment. Cluster analysis shows the Pattani specimens clustering with the Malaysian specimens rather than the Thai specimens, suggesting homogeneous morphometric data between contiguous sites. Nakhon and Pattani forming separate groups in both species suggest discreet subpopulations occurring in the lower Gulf of Thailand. Patterns of phenotypic variation observed may be attributable to environmental conditions, local adaptations, and nomadic behavior. The findings can serve as baseline information for spatial planning in fisheries management, as well as to apprise regional efforts in the sustainable exploitation of Thenus spp.

Keywords: Flathead lobster; Discriminant function; Cluster analysis; Fisheries management

INTRODUCTION

Thenus Leach, 1816 is made up of five species that are commercially valuable as food and popular in a variety of cuisines. Thenus spp., commonly known as flathead lobsters, are among the edible species in the slipper lobster family Scyllaridae Latreille, 1825 due to their larger size compared to other scyllarids (Holthius, 1991). They are the few scyllarids with full aquaculture because of their relatively short life cycle, quick growth, resilient larvae, and non-aggressive behavior in culture settings (Rogers et al., 2010). There has been success in Thenus spp. aquaculture at experimental levels in Australia (Mikami and Kuballa, 2004) and India (Kizkhakudan et al., 2004). Recently, the Aquaculture Department of the Southeast Asian Fisheries Development Centre (AQD SEAFDEC) has begun developing an aquaculture program for T. orientalis in tropical conditions, achieving the notable milestone of spawning and egg-hatching in captivity (SEAFDEC, 2022). It is predicted that once commercial aquaculture is formed, Thenus aquaculture output will be a valuable source of food and income (Jeffs et al., 2020).

Thenus spp. are typically landed as bycatch of trawl fisheries. Currently, data on the wild populations of Thenus are scarce, despite continuous exploitation. The International Union for Conservation of Nature (IUCN) Red List categorizes members of this genus as “data deficient” indicating a dearth of data on Thenus spp. population status, distribution, and trends, as well as habitat and threats (IUCN, 2023). While large-scale aquaculture remains under development, the wild population continues to be exploited incidentally as the sole source of flathead lobsters for commercial purposes. This continuous exploitation, without comprehensive data, could be detrimental to their survival. For example, overexploitation led to a collapse of the T. orientalis population in Mumbai, India which has yet to recover (Jeena et al., 2019). Therefore, it is crucial to collect data on wild Thenus populations to inform fisheries management plans for the sustainable exploitation of this resource.

Phenotypic variation is often used to describe populations in a distribution range of commercial species (Chandran et al., 2022). Multivariate analyses of morphometric characters are consistently used to study the stocks of exploited crustacean species (Chybowski, 2014; Jónsdóttir et al., 2016; Du et al., 2022). Discriminant function and cluster analyses are prevalent techniques to detect phenotypic variation, since their results can be foundational data for characterizing populations and their interconnectivity (García-Dávila et al., 2005; Siddik et al., 2016). This study employed multivariate methods to investigate phenotypic variation in Thenus spp. present in the waters of Malaysia and southern Thailand to provide population information to support fisheries management within the region. Disparities in scyllarid body forms have often been attributed to environmental factors and behavioral adaptations for habitat exploitation (Jones, 2007; Spanier et al., 2010). It would be informative to see how the species differ now, since studies indicate different preferences in water depth and sediment composition for each species (Jones, 1993, 2007; Iamsuwansuk et al., 2012). Phenotypic variation between sites is analyzed to identify discrete populations within the region. Phenotypic variation can be an indicator for discrete populations, which is useful to distinguish conservation units and to plan fisheries management systems (Zhang et al., 2016; Jawad et al., 2021).

Thus, this study aims to determine the pattern of phenotypic variation between selected sites for T. orientalis and T. indicus, respectively. This endeavor is a suitable first step in researching Malaysia’s unknown Thenus spp. population and it is beneficial in updating information on the Thenus spp. present in southern Thailand. Furthermore, we can determine whether fisheries management of Thenus spp. can be incorporated as a regional effort between these neighboring countries.

METHODS

SAMPLE COLLECTION

Dead specimens of Thenus spp. that were entirely frozen in ice were collected from seven commercial lobster landing sites in Malaysia and southern Thailand (Figure 1). The sampling locations in Malaysia were divided into two main regions: Kota Kinabalu (KK) and Kudat (KD), representing East Malaysia on the Borneo Island, while Kuala Terengganu (KT) and Tanjung Sedili (TS) representing the Peninsular Malaysia. Meanwhile, the sampling locations in southern Thailand were Pattani (PT) and Nakhon Si Thammarat (NK), located on the Gulf of Thailand, and Ranong (RN), on the Andaman Sea side.

Figure 1
Map of sampling locations in Malaysia and southern Thailand.

MORPHOLOGICAL EXAMINATION AND MORPHOMETRIC MEASUREMENTS

Each specimen was physically examined to distinguish the morphological characteristics as described in the identification key provided by Burton and Davie (2007). Male and female specimens were differentiated macroscopically according to their sexual dimorphic characteristics, based on the position of gonophores at the third pereiopods for females and the fifth pereiopods for males (Alborés et al., 2019). Each individual was weighed, labelled, and photographed. Total length in addition to twenty-five other morphometric measurements of the body, carapace (dorsally measured), antennae, the propodus and merus of the first three pereiopods, two abdomen segments (dorsally measured), and telson of each specimen were taken using Vernier calipers (Figure 2, Table 1).

Figure 2
Morphometric measurements of Thenus spp. Leach, 1816. A: carapace and abdomen (dorsally measured); B: antennae; C: first, second, and third pereiopods. Modified from Burton and Davie (2007).

Table 1
Definitions of morphometric characters of Thenus spp. Leach, 1816 used for this study based on Burton and Davie (2007).

DATA ANALYSIS

Descriptive statistics viz. mean, standard deviation, minimum value, and maximum value were produced for the morphometric measurements. The measurements were log-transformed for data linearization (Chandran et al., 2022). Size-dependent variation in the morphometric measurements was eliminated using the allometric method, proposed by Elliott et al. (1995). The equation was:

Madj=M(LSL0)b

In the equation, M is the original measurement, Madj is the adjusted measurement, L0 is the total length of the slipper lobster, Ls is the overall mean of the total length for all the slipper lobsters from all sampling sites, and b is the slope of the regression of logM against logL0 using all slipper lobsters from all sampling sites. Successful removal of size variation was confirmed by testing the significance of the correlation between the adjusted measurements derived from the allometric method and the total length. Total length was excluded from subsequent multivariate analysis because it was used as a basis for the transformation (Jaferian et al., 2010; Siddik et al., 2016; Zhang et al., 2016).

Thus, the other twenty-five size-adjusted morphometric measurements of the carapace, antennae, abdomen, pereiopods, and telson of Thenus spp. (n = 107) were subjected to canonical discriminant function analysis (CDFA) and hierarchical cluster analysis (CA) to examine patterns of phenotypic variation (García-Dávila et al., 2005; Wardiatno et al., 2021). CDFA was conducted to detect significant morphometric character variation between sites. Factor loading values of more than 0.3 are deemed significant, of which 0.4 is more significant and 0.5 or higher is extremely significant (Nimalathasan, 2009). Therefore, only the loading values greater than 0.4 were considered significantly important. Cross-validated classification results from discriminant analysis were used to evaluate the accuracy of group classifications. Dendrograms derived from CA, based on squared Euclidean distances between the groups of centroids, were used to display the relation and degree of similarity between the analyzed groups. All the statistical analyses in this study were conducted using Microsoft Excel and SPSS v. 27.

RESULTS

GENERAL CHARACTERISTICS

Table 2 shows the number of specimens collected by sex, and the range and mean (± SD) values for the total length (cm) and total weight (g) of Thenus spp. from the seven sampling locations in Malaysia and southern Thailand. Supplementary Material 1 shows the mean (± SD) lengths of the twenty-five morphometric characters of Thenus spp. analyzed by sites. Individuals of T. orientalis were collected from four sites (Kota Kinabalu; Kudat; Pattani; and Nakhon Si Thammarat), while T. indicus specimens were collected from six sites (Kota Kinabalu; Kuala Terengganu; Tanjung Sedili; Pattani; Nakhon Si Thammarat; and Ranong). The total length and weight of overall individuals collected ranged from 11.9 to 24.4 cm and 56.0 to 291.0 g for T. orientalis; and 10.8 to 26.7 cm and 35.0 to 312 g for T. indicus, respectively. The largest T. orientalis specimen was collected from the Kudat site (female, 24.4 cm, 291.0 g) while the smallest specimens were collected from the Pattani site (male, 11.9 cm, 60.7 g; and male, 12.84 cm, 56.0 g). Specimens of T. orientalis that were collected from the Nakhon Si Thammarat site had the highest mean values of total length and weight (19.5±2.56 cm, 195.5±47.19 g) while the smallest values were from Pattani (14.6±2.88 cm, 99.6±45.86 g). T. indicus specimens collected from the Ranong site had the highest mean total length and weight (18.6±1.50 cm, 177.2±12.2 g) while specimens from the Tanjung Sedili site had the lowest (13.1±0.95cm, 67.3±11.53 g). The largest T. indicus specimen was collected from the Kota Kinabalu site (female, 26.7 cm, 312.0 g), while the smallest specimens were collected from the Pattani (male, 10.8 cm, 52.9 g) and Kuala Terengganu (female, 11.0 cm, 35.0 g) sites. These three individuals also comprise the largest and smallest Thenus specimens collected in the whole study. In terms of sex, females were generally larger than males for all both species, of which the largest specimen collected overall was the female T. indicus from Kota Kinabalu.

Table 2
Total length (mean±SD, cm) and weight (mean±SD, g) of Thenus spp. Leach, 1816 specimens analyzed in this study from Malaysia and southern Thailand.

PHENOTYPIC VARIATION BETWEEN SITES

Between the four sites where T. orientalis were collected, the CDFA provided three canonical discriminant functions with Wilk’s lambda values ranging from 0.0001 to 0.26, with statistically significant values (p < 0.01) (Table 3). The first function provided 77.2% of the total variance between sites, while the second function contributed 18.0%, so the first two factors cumulatively explained 95.2% of the entire variation. The third function had weak discriminatory power and only explained 4.8% of the total variance. In the first function, the morphometric characters with the greatest effect in separating the sites of T. orientalis were CW2, A1L, A2L, ML1, MW2, ML3, MW3, AL1, and AW1 (Table 4). Overall, the variation between T. orientalis sites was best explained by the width of the merus of the third pereiopods (MW3), the width of the sixth abdomen segment (AW2), and the width of the posterior margin of the carapace (CW2) by DF1, DF2, and DF3, respectively. By comparison, these characters were notably greater in size in the Nakhon Si Thammarat specimens than the Pattani, Kota Kinabalu, and Kudat specimens (Supplementary Material 1).

Table 3
Summary of canonical discriminant function and Wilk’s lambda test for verifying differences between the sites for T. orientalis and T. indicus, respectively, morphometric characters using CDFA.

Table 4
The standardized canonical discriminant function coeffcients from CDFA of T. orientalis and T. indicus between sites, respectively.

The scatter plot revealed significant differences between the four sites as distinct centroids (Figure 3a). While the T. orientalis cases of Kota Kinabalu and Kudat showed a high degree of overlap to form one group, the cases of Pattani and Nakhon Si Thammarat formed two separate groups. Cross-validation classification showed that the discriminant analysis correctly classified 85.4% of the T. orientalis specimens from the four sites overall (Table 5). The best cross-validated classification rate was obtained for Nakhon Si Thammarat cases at 100%, followed by Kudat cases at 85.7%. Also, the cross-validation classification results showed two intermixing groups occurring as (i) Pattani and Kota Kinabalu and (ii) Kota Kinabalu and Kudat. Meanwhile, the Nakhon Si Thammarat cases stood alone. The dendrogram shows the relation of the T. orientalis sites as two main clusters, where the cases of Kota Kinabalu and Kudat formed one cluster, while the cases of Pattani and Nakhon Si Thammarat formed the other cluster before fragmenting into individual groups (Figure 4a).

Figure 3
Scatterplot of the discriminant function scores from the analysis of 25 morphometric characters for Thenus spp. from Malaysia and Thailand. A, four sites of T. orientalis Lund, 1793 (n = 48); and B, six sites of T. indicus Leach, 1816 (n = 59).

Table 5
Predicted classification results from discriminant analysis among sites for T. orientalis and T. indicus, respectively. Numbers in bold indicate the percentage of classification success (%). Corresponding numbers of individuals are shown in parentheses.

Figure 4
Dendrogram derived from cluster analysis of morphometric characters based on squared Euclidean distances between the groups of centroids. A, four sites of T. orientalis Lund, 1793; and B, six sites of T. indicus Leach, 1816 from Malaysia and Thailand. The horizontal axis numbers indicate average joins among populations.

Between the six sites where T. indicus were collected, the CDFA yielded four canonical discriminant functions with Wilk’s lambda values ranging from 0.0001 to 0.16 and significant chi-square values (p < 0.001). The first two functions cumulatively explained 97.1% of the total variation, for which the first function contributed the most to the total variance between sites at 85.1%, followed by the second function at 12.0% (Table 3). The third and fourth functions contributed very little to the total variance - 1.6% and 0.9%, respectively - and had extremely poor discriminatory power. The fifth function was not statistically significant. The morphometric characters with the greatest impact on separating sites of T. indicus in the first function were A2W, PW1, ML1, ML3, AL2, TL, TW, and CW2 (Table 4). A2W explained most of the variation in the first function, while AL2 explained most of the variation in the third function, and MW1 explained most of the variation in the second and fourth functions. Overall, the morphometric characters that best discriminated T. indicus sites were the width of the second antenna (A2W), the length of the sixth abdomen segment (AL2), and the width of the merus of the first pereiopods (MW1). Generally, specimens from Pattani, Tanjung Sedili, and Kuala Terengganu had smaller widths in their second antennae and merus of the first pereiopods compared to those of the other three sites (Supplementary Material 1). They also had greater lengths in their sixth abdomen segments compared to those of the other sites except for Kota Kinabalu.

The scatter plot displays a high degree of overlap in the morphometric data between the sites with distinct but close centroids forming three groups: (i) Ranong and Nakhon Si Thammarat; (ii) Kota Kinabalu, Tanjung Sedili, and Kuala Terengganu, and (iii) Pattani (Figure 3b). The overall cross-validated classification results show that 86.4% of the T. indicus specimens were correctly classified for the six sites (Table 6). The best cross-validated classification rates were obtained for the T. indicus cases in Pattani, Nakhon Si Thammarat, and Tanjung Sedili, each at 100% with no intermixing observed with other sites. The cross-validated classification results indicated two intermixing groups: (i) Ranong and Nakhon Si Thammarat, (ii) Kota Kinabalu, Kuala Terengganu, and Tanjung Sedili. The dendrogram provided clarity on the relation by showing the degree of similarity between the overlapping cases (Figure 4b). The sites are initially divided into two clusters: Nakhon Si Thammarat and Ranong cases in one cluster, and the Pattani and Malaysian cases in the other. The cases of Kuala Terengganu, Tanjung Sedili, and Kota Kinabalu are clustered further, apart from the Pattani cases, to form a sub-cluster.

DISCUSSION

Thenus was previously considered monotypic, with T. orientalis Lund, 1793 as the sole member. However, Burton and Davie (2007) published a taxonomic review distinguishing five separate Thenus species based on morphological characteristics, morphometric ratios, and molecular data. Since then, Thenus populations have been studied worldwide to corroborate species composition and distribution, such as in India (Jeena et al., 2015; Anuraj et al., 2017) and Indonesia (Wardiatno et al., 2016; Wiadnyana et al., 2019). This study updates distribution records of Thenus spp. in Malaysia and southern Thailand, where a total of two species of Thenus were found. T. indicus was the most frequently captured species in the trawl fisheries of both countries, as it was collected in most of the landing sites. The T. indicus collection in Ranong updated a past distribution report on Thenus spp. in Thailand that expected this species to be present, but did not report it (Iamsuwansuk et al., 2012). Contrastingly, T. orientalis was not found in the Andaman Sea, but was prevalent in the sites of the Gulf of Thailand and the South China Sea. This study collected T. indicus specimens from Tanjung Sedili, which is also an update on the distribution range of this species, since past reports had only noted T. orientalis in Johor waters (Siow et al., 2018, 2020). Iamsuwansuk et al. (2012) suggested that the distribution pattern of Thenus spp. in the region is influenced by the availability of preferred habitat conditions of each species, in which T. indicus prefer shallower water close to the coast, while T. orientalis were more common in the deeper waters of the open sea (Iamsuwansuk et al., 2012). For sediment composition, T. orientalis tend to inhabit sandy, coarse, and muddy substrates with shells and gravel (Kizkhakudan et al., 2004; Chan et al., 2011; Saher et al., 2018), while T. indicus prefer fine mud and silty inshore substrates (Butler et al., 2011). The pereiopods are particularly significant in scyllarid feeding and concealment behavior (Lau, 1987; Jones, 2007). Thenus spp. are highly skilled in handling and opening shells using their pereiopods (Lau, 1987), which supports their preference for molluscan prey (Jones, 2007). The pereiopods, as well as the abdomen and antennal segments, are also involved in the hydrodynamics of scyllarid swimming (Spanier et al., 2010).

Multivariate analyses on twenty-five morphometric characters were successful in demonstrating significant phenotypic variation between selected sites for T. orientalis and T. indicus. The results of the CDFA and CA supported each other in displaying the patterns of significant phenotypic variation between selected sites for T. orientalis and T. indicus. Between the four sites for T. orientalis, the morphometric data showed significant phenotypic variation and separated the sites into three groups viz. (i) Kota Kinabalu and Kudat, (ii) Pattani, and (iii) Nakhon Si Thammarat. The strongest predictors were the pereiopods, abdomen, and carapace. These elements were larger in the Nakhon specimens than in those of Pattani, Kota Kinabalu, and Kudat. Kota Kinabalu and Kudat share similar morphometric data, suggesting a subpopulation of T. orientalis in Sabahan waters, while Pattani and Nakhon form separate clusters, suggesting two distinct subpopulations of T. orientalis occurring in the lower Gulf of Thailand. Intermixing morphometric data between specimens of Pattani and Kota Kinabalu suggests morphological similarities between the individuals of these two distant sites. Between the six sites for T. indicus, the morphometric data showed significant phenotypic variation and separated the sites into three groups viz. (i) Ranong and Nakhon Si Thammarat; (ii) Kota Kinabalu, Tanjung Sedili, and Kuala Terengganu; and (iii) Pattani. The best descriptors were the antenna, pereiopods, and abdomen, and the specimens of Pattani, Tanjung Sedili, and Kuala Terengganu, differed from the other three sites in these characters. The three Malaysian sites showing very similar morphometric data suggest a single population of T. indicus occurring in Malaysian waters. The CA dendrogram showing the Pattani specimens clustering with the Malaysian sites rather than Nakhon, suggests a close morphological similarity between contiguous sites that does not extend further up the Gulf. This suggests that two distinct subpopulations might exist in the lower Gulf for T. indicus, as well. The morphological characters that best differentiated individuals were those related to feeding, burying, and swimming, namely the pereiopods, abdomen, and antenna. This may suggest that the variations observed might be due to adaptations to the local habitat and environmental conditions (Zhang et al., 2016; Chandran et al., 2022). The Gulf’s bathymetry (Morley, 2015; Waewsak et al., 2015) and seasonal current circulations (Sojisuporn et al., 2010; Wang et al., 2020) may play a role in affecting movement and food availability. Ranong and Nakhon specimens clustering together suggests they share morphological similarities despite being the most geographically distant, occurring in two separate waterbodies on either side of Thailand. This may indicate that the two locations share similar environmental conditions (Zhang et al. 2016; Wardiatno et al., 2021). Further study is required to confirm the similarities and differences in habitat and environmental conditions between these locations.

This study characterized the populations of Thenus spp. in Malaysia and Thailand, which can serve as baseline information for sustainable fisheries management, especially in spatial planning. Morphometric differences suggest a complexity of stock structure, possibly indicating subpopulations that would require fisheries managers to redefine management units for the best strategy of exploitation (Zhang et al., 2016; Wardiatno et al., 2021). Common spatial tools in fisheries management within the region are fishing zones and marine protected areas (Garces et al., 2006; Nootmorn, 2020). If existing management zones are inconsistent with assemblage patterns, fishermen are potentially fishing the same stock despite sectors being spatially segregated (Garces et al., 2006). Although fishing zones in the Malaysian exclusive economic zone (EEZ) are segregated state-wise, the fishermen may be fishing the same stock of Thenus spp. It would be valuable for monitoring purposes to know that similar habitat conditions in distant sites develop similar morphometric data. A population study for T. indicus in the upper Gulf of Thailand found it to be genetically homogenous (Iamsuwansuk et al., 2012), while this study found T. indicus in the lower Gulf to be phenotypically varied, which suggests a possible divide between Nakhon and Pattani that should be considered for fisheries management. It is important to note isolated spatial structures during management to maintain spawning components and genetic diversity (Zhang et al., 2016). Regional efforts with neighboring countries collaboration to manage Thenus spp. may be possible due to the morphometric similarity between Pattani and Malaysian sites, indicating phenotypic homogeneity between contiguous sites.

Further studies should explore the genetic characteristics between sites to clarify the morphological homogeneity, especially between geographically distant sites. An analysis of the genetic diversity of Thenus spp. in Malaysian waters might also observe a narrow genetic diversity between sites to support the homogeneous phenotypic data. A genetic study in the lower Gulf of Thailand would also be informative to investigate a possible genetic barrier between the two sites.

ACKNOWLEDGMENTS

This research was supported by the UMSGreat Fasa 2/2019 Grant (GUGU428-2/2019) provided by Universiti Malaysia Sabah. The authors would like to thank the Discipline of Excellence for Sustainable Aquaculture, Prince of Songkla University, for scholarship during the graduate candidature of the first author. The authors are also grateful to the Borneo Marine Research Institute (Universiti Malaysia Sabah) and the Faculty of Science and Technology (Prince of Songkla University) for providing the facilities, as well as administrative and logistic support for data collection and analysis.

REFERENCES

  • Alborés, I., García-Soler, C. & Fernández, L. 2019. Reproductive biology of the slipper lobster Scyllarus arctus in Galicia (NW Spain): Implications for fisheries management. Fisheries Research, 212, 1-11. DOI: https://doi.org/10.1016/j.fishres.2018.12.001
    » https://doi.org/https://doi.org/10.1016/j.fishres.2018.12.001
  • Anuraj, A., Kirubasankar, R., Kaliyamoorthy, M. & Dam Roy, S. 2017. Genetic evidence and morphometry for shovel nosed lobster, Thenus unimaculatus from Andaman and Nicobar Islands, India. Turkish Journal of Fisheries and Aquatic Sciences, 17, 209-215. DOI: https://doi. org/10.4194/1303-2712-v17_1_23
    » https://doi.org/https://doi. org/10.4194/1303-2712-v17_1_23
  • Burton, T. E. & Davie, P. J. F. 2007. A revision of the shovel-nosed lobsters of the genus Thenus (Crustacea: Decapoda: Scyllaridae), with descriptions of three new species. Zootaxa, 1429(1), 1-38. DOI: https://doi.org/10.11646/zootaxa.1429.1.1
    » https://doi.org/https://doi.org/10.11646/zootaxa.1429.1.1
  • Butler, M., Chan, T. Y., Cockroft, A., MacDiarmid, A., Ng, H. H. & Wahle, R. 2011. Thenus indicus. The IUCN Red List of Threatened Species 2011. DOI: https://dx.doi.org/10.2305/IUCN.UK.2011-1.RLTS.T185014A8348228.en
    » https://doi.org/https://dx.doi.org/10.2305/IUCN.UK.2011-1.RLTS.T185014A8348228.en
  • Chan, T. Y., Butler, M., Cockroft, A., MacDiarmid, A., Wahle, R. & Ng Kee Lin, P. 2011. Thenus orientalis. The IUCN Red List of Threatened Species 2011 . DOI: https://dx.doi.org/10.2305/IUCN.UK.2011-1.RLTS.T169979A6698039.en
    » https://doi.org/https://dx.doi.org/10.2305/IUCN.UK.2011-1.RLTS.T169979A6698039.en
  • Chandran, R., Singh, A., Singh, R. K., Mandal, S., Ganesan, K., Sah, P., Paul, P., Pathak, A., Dutta, N. & Sah, R. 2022. Phenotypic variation of Chitala chitala (Hamilton, 1822) from Indian rivers using truss network and geometric morphometrics. PeerJ, 10, e13290. DOI: https://dx.doi.org/10.7717/peerj.13290
    » https://doi.org/https://dx.doi.org/10.7717/peerj.13290
  • Chybowski, Ł. 2014. Morphometric differentiation in four populations of signal crayfish, Pacifastacus leniusculus (Dana), in Poland. Fisheries & Aquatic Life, 22(3), 229-233. DOI: https://dx.doi.org/10.2478/aopf-2014-0023
    » https://doi.org/https://dx.doi.org/10.2478/aopf-2014-0023
  • Du, J., Hou, C., Chen, X., Xiao, J., Gul, Y. & Wang, H. 2022. Morphometric analysis and fluorescent microsatellite markers to evaluate the genetic diversity of five populations of Penaeus japonicus in China. Aquaculture and Fisheries, 7(3), 321-327. DOI: https://doi.org/10.1016/j.aaf.2020.10.005
    » https://doi.org/https://doi.org/10.1016/j.aaf.2020.10.005
  • Elliott, N. G., Haskard, K. & Koslow, J. A. 1995. Morphometric analysis of orange roughy (Hoplostethus atlanticus) off the continental slope of southern Australia. Journal of Fish Biology, 46(2), 202-220. DOI: https://doi.org/10.1111/j.1095-8649.1995.tb05962.x
    » https://doi.org/https://doi.org/10.1111/j.1095-8649.1995.tb05962.x
  • Garces, L. R., Stobutzki, I., Alias, M., Campos, W., Koongchai, N., Lachica-Alino, L., Mustafa, G., Nurhakim, S., Srinath, M. & Silvestre, G. 2006. Spatial structure of demersal fish assemblages in South and Southeast Asia and implications for fisheries management. Fisheries Research , 78(2), 143-157. DOI: https://doi.org/10.1016/j.fishres.2006.02.005
    » https://doi.org/https://doi.org/10.1016/j.fishres.2006.02.005
  • García-Dávila, C. R., Magalhães, C. & Guerrero, J. C. H. 2005. Morphometric variability in populations of Palaemonetes spp.(Crustacea, Decapoda, Palaemonidae) from the Peruvian and Brazilian Amazon Basin. Iheringia. Série Zoologia, 95, 327-334. DOI: https://doi.org/10.1590/S0073-47212005000300013
    » https://doi.org/https://doi.org/10.1590/S0073-47212005000300013
  • Holthius, L. B. 1991. Marine lobsters of the world: An annotated and illustrated catalogue of species of interest to fisheries known to date (FAO Fisheries and Synopsis, 13th vol., no. 145). Rome: FAO-UN.
  • Iamsuwansuk, A., Denduangboripant, J. & Davie, P. 2012. Molecular and morphological investigations of shovel-nosed lobsters Thenus spp. (Crustacea: Decapoda: Scyllaridae) in Thailand. Zoological Studies, 51(1), 108-117. Available from: Available from: https://zoolstud.sinica.edu.tw/Journals/51.1/108.html Access date: 2024 out 14.
    » https://zoolstud.sinica.edu.tw/Journals/51.1/108.html
  • IUCN. 2023. The IUCN Red List of Threatened Species. Version 2022-2. Available from: Available from: https://www.iucnredlist.org/ Access date: 2023 Aug 19.
    » https://www.iucnredlist.org/
  • Jaferian, A., Zolgharnein, H., Mohammadi, M., Salari-Aliabadi, M.-A. & Hossini, S.-J. 2010. Morphometric study of Eleutheronema tetradactylum in Persian Gulf based on the truss network. World Journal of Fish and Marine Sciences, 6, 499-504. Available from: Available from: https://www.idosi.org/wjfms/wjfms2(6)10/5.pdf Access date: 2024 out 14.
    » https://www.idosi.org/wjfms/wjfms2(6)10/5.pdf
  • Jawad, L. A., Abed, J. M. & Ibáňez, A. L. 2021. Stock differentiation of the greater lizardfish Saurida tumbil (Teleostei: Synodontidae) collected along the western coast of the Arabian Gulf and Sea of Oman using meristic characters. Journal of Fish Biology , 99(2), 495-501. DOI: https://doi.org/10.1111/jfb.14739
    » https://doi.org/https://doi.org/10.1111/jfb.14739
  • Jeena, N. S., Gopalakrishnan, A., Radhakrishnan, E. V., Kizkhakudan, J. K., Basheer, V. S., Asokan, P. K. & Jena, J. K. 2015. Molecular phylogeny of commercially important lobster species from Indian coast inferred from mitochondrial and nuclear DNA sequences. Mitochondrial DNA, 2700-2709. DOI: https://doi.org/10.3109/19401736.2015.1046160
    » https://doi.org/https://doi.org/10.3109/19401736.2015.1046160
  • Jeena, N. S., Gopalakrishnan, A., Radhakrishnan, E. V., Kizkhakudan, J. K. & Jena, J. K. 2019. Applications of molecular tools in systematics and population genetics of lobsters. In: Radhakrishnan, E. V., Phillips, B. & Gopalakrishnan, A. (Ed.). Lobsters: Biology, Fisheries and Aquaculture (pp. 125-150). Singapore: Springer Nature.
  • Jeffs, A., Daniels, C. & Heasman, K. 2020. Aquaculture of Marine Lobsters. In: Lovrich, G. & Thiel, M. (Ed.). Fisheries and Aquaculture: Volume 9 (pp. 285-312). Oxford: Oxford University Press.
  • Jones, C. 1993. Population structure of Thenus orientalis and T. indicus (Decapoda: Scyllaridae) in northeastern Australia. Marine Ecology Progress Series, 97, 143-153. Accessed: Accessed: https://researchonline.jcu.edu. au/28384/1/28384_CJones_1993.pdf Access date: 2024 out 14.
    » https://researchonline.jcu.edu. au/28384/1/28384_CJones_1993.pdf
  • Jones, C. 2007. Biology and fishery of the Bay Lobster, Thenus spp. In: Lavalli, K. & Spanier, E. (Ed.). The Biology and Fisheries of the Slipper Lobster (pp. 325-358). Boca Raton: CRC Press.
  • Jónsdóttir, I. G., Guðlaugsdóttir, A. K. & Karlsson, H. 2016. Morphometric differences between sub-populations of northern shrimp (Pandalus borealis): A case study from two adjacent fjords in Iceland. Regional Studies in Marine Science, 3, 42-48. DOI: https://doi.org/10.1016/j.rsma.2015.04.002
    » https://doi.org/https://doi.org/10.1016/j.rsma.2015.04.002
  • Kizkhakudan, J. K., Thirumilu, P., Rajapackiam, S. & Manibal, C. 2004. Captive breeding and seed production of scyllarid lobsters-opening new vistas in crustacean aquaculture (Marine Fisheries Information Sevice, no. 181). Cochin: Central Marine Fisheries Research Institute.
  • Lau, C. J. 1987. Feeding behavior of the hawaiian slipper lobster, scyllarides squammosus, with a review of decapod feeding tactics on molluscan prey. Bulletin of Marine Science, 41(2), 378-391. Available from: Available from: https://www.ingentaconnect.com/content/umrsmas/bullmar/1987/00000041/00000002/art00024# Access date: 2024 out 14.
    » https://www.ingentaconnect.com/content/umrsmas/bullmar/1987/00000041/00000002/art00024#
  • Mikami, S. & Kuballa, A. 2004. Overview of lobster aquaculture research. In: Hatchery Feeds and Technology Workshop (2. ed., pp. 127-130).
  • Morley, C. K. 2015. Five anomalous structural aspects of rift basins in Thailand and their impact on petroleum systems. Geological Society, London, Special Publications, 421(1), 143-168. DOI: https://doi.org/10.1144/SP421.2
    » https://doi.org/https://doi.org/10.1144/SP421.2
  • Nimalathasan, B. 2009. Determinants of key performance indicators (KPIS) of private sector banks in Sri Lanka: an application of exploratory factor analysis. The Annals of the Ştefan Cel Mare University of Suceava : Fascicle of the Faculty of Economics and Public Administration Vol.9, 2(10), 9-17. Available from: Available from: https://ssrn.com/abstract=2117277 Access date: 2024 out 14.
    » https://ssrn.com/abstract=2117277
  • Nootmorn, P. 2020. Regulation and Fisheries Management for Fisheries Refugia in Thailand. Report (Southeast Asian Fisheries Development Center Project). Thailand: Southeast Asian Fisheries Development Center Training Department.
  • Rogers, P., Barnard, R. & Johnston, M. 2010. Lobster aquaculture a commercial reality: a review. Journal of the Marine Biological Association of India, 52(2), 327-335. Available from: Available from: https://www.mbai.org.in/jmbai-details/MjE3OA==/MTAy Access date: 2024 out 14.
    » https://www.mbai.org.in/jmbai-details/MjE3OA==/MTAy
  • Saher, N. U., Naz, F., Noor, S. H. & Kamal, M. 2018. A new record of shovel-nosed lobster Thenus unimaculatus Burton and Davie 2007 (Crustacea: Decapoda: Scyllaridae) from the coastal waters of Pakistan. Thalassas, 35(1), 223-228. DOI: https://doi.org/10.1007/s41208-018-0113-y
    » https://doi.org/https://doi.org/10.1007/s41208-018-0113-y
  • SEAFDEC. 2022. SEAFDEC Annual Report 2021. Bangkok: Southeast Asian Fisheries Development Center.
  • Siddik, M. A. B., Hanif, M. A., Chaklader, M. R., Nahar, A. & Fotedar, R. 2016. A multivariate morphometric investigation to delineate stock structure of gangetic whiting, Sillaginopsis panijus (Teleostei: Sillaginidae). SpringerPlus, 5, 1-13. DOI: https://doi.org/10.1186/s40064-016-2143-3
    » https://doi.org/https://doi.org/10.1186/s40064-016-2143-3
  • Siow, R., Ahmad Arshad, A. H. H. & Asgnari, N. H. 2018. Establishment and Operation of a Regional System of Fisheries Refugia in the South China Sea and Gulf of Thailand. Report (Lobster Resource Study in East Johor). Malaysia: Southeast Asian Fisheries Development Center, Training Department.
  • Siow, R., Nurridan, A. H., Hadil, R. & Richard, R. 2020. The establishment of fisheries refugia as a new approach to sustainable management of fisheries in Malaysian waters. IOP Conference Series: Earth and Environmental Science, 414(1), 012023. DOI: https://doi.org/10.1088/1755-1315/414/1/012023
    » https://doi.org/https://doi.org/10.1088/1755-1315/414/1/012023
  • Sojisuporn, P., Morimoto, A. & Yanagi, T. 2010. Seasonal variation of sea surface current in the Gulf of Thailand. Coastal Marine Science, 34(1), 91-102. DOI: https://doi.org/10.4186/ej.2017.21.4.25
    » https://doi.org/https://doi.org/10.4186/ej.2017.21.4.25
  • Spanier, E., Lavalli, K. & Weihs, D. 2010. Comparative morphology in slipper lobsters: possible adaptations to habitat and swimming, with emphasis on lobsters from the Mediterranean and adjacent seas. Monografie Del Museo Regionale Di Scienze Naturali Di Torino, 111-130. Available from: Available from: https://cris.technion.ac.il/en/publications/comparative-morphology-in-slipper-lobsters-possible-adaptations-t Access date: 2024 out 14.
    » https://cris.technion.ac.il/en/publications/comparative-morphology-in-slipper-lobsters-possible-adaptations-t
  • Waewsak, J., Landry, M. & Gagnon, Y. 2015. Offshore wind power potential of the Gulf of Thailand. Renewable Energy, 81, 609-626. DOI: https://doi.org/10.1016/j.renene.2015.03.069
    » https://doi.org/https://doi.org/10.1016/j.renene.2015.03.069
  • Wang, Y., Zou, X., Peng, C., Qiao, S., Wang, T., Yu, W., Khokiattiwong, S. & Kornkanitnan, N. 2020. Occurrence and distribution of microplastics in surface sediments from the Gulf of Thailand. Marine Pollution Bulletin, 152, 110916. DOI: https://doi.org/10.1016/j.marpolbul.2020.110916
    » https://doi.org/https://doi.org/10.1016/j.marpolbul.2020.110916
  • Wardiatno, Y., Aziz, A., Meilana, L. & Hakim, A. A. 2021. A morphometric approach into mackerel (Rastrelliger spp.) diversity in Fisheries Management Area 711 as a management base. In: IOP Conference Series: Earth and Environmental Science (Vol. 744, 012096). DOI: https://doi.org/10.1088/1755-1315/744/1/012096
    » https://doi.org/https://doi.org/10.1088/1755-1315/744/1/012096
  • Wardiatno, Y., Hakim, A. A., Mashar, A., Butet, N. A. & Adrianto, L. 2016. Two newly recorded species of the lobster Family Scyllaridae (Thenus indicus and Scyllarides haanii) from South of Java, Indonesia. HAYATI Journal of Biosciences, 23(3), 101-105. DOI: https://doi.org/10.1016/j.hjb.2016.05.001
    » https://doi.org/https://doi.org/10.1016/j.hjb.2016.05.001
  • Wiadnyana, N. N., Triharyuni, S. & Prihatiningsih. 2019. Sex ratio, length at first capture and catch per-unit effort of slipper lobsters (Scyllaridae) in Kupang and surrounding waters. Jurnal Penelitian Perikanan Indonesia, 25(1), 27. DOI: https://doi.org/10.15578/jppi.25.1.2019.27-34
    » https://doi.org/https://doi.org/10.15578/jppi.25.1.2019.27-34
  • Zhang, C., Jiang, Y., Ye, Z., Li, Z. & Dou, S. 2016. A morphometric investigation of the small yellow croaker (Larimichthys polyactis Bleeker, 1877): evidence for subpopulations on the Chinese coast. Journal of Applied Ichthyology, 32(1), 67-74. DOI: https://doi.org/10.1111/jai.12923
    » https://doi.org/https://doi.org/10.1111/jai.12923

Edited by

  • Associate Editor:
    Margit Wilhelm

Publication Dates

  • Publication in this collection
    10 Jan 2025
  • Date of issue
    2024

History

  • Received
    15 July 2024
  • Accepted
    04 Oct 2024
location_on
Instituto Oceanográfico da Universidade de São Paulo Praça do Oceanográfico 191, CEP: 05508-120, São Paulo, SP - Brasil, Tel.: (11) 3091-6501 - São Paulo - SP - Brazil
E-mail: diretoria.io@usp.br
rss_feed Acompanhe os números deste periódico no seu leitor de RSS
Acessibilidade / Reportar erro