Meristic Measurements Research Articles

Declines and shifts in morphological diversity of ciscoes (Coregonus spp.) in lakes Huron and Michigan, 1917–2019

Ciscoes ( Coregonus spp .) were historically abundant and ecologically important in Laurentian Great Lakes ecosystems. Despite well-documented declines in their abundance and taxonomic diversity, declines in morphological diversity remain understudied. This knowledge gap is especially pertinent for lakes Michigan and Huron, which have each lost six of eight historical species. Improved understanding of historical and contemporary morphological diversity of Great Lakes ciscoes can inform ongoing restoration efforts and further elucidate the factors that contributed to declines. Our goal was to characterize shifts in morphological diversity of ciscoes in lakes Michigan and Huron over a century (1917–2019). We analyzed size-corrected morphometric and meristic measurements from three periods: Early (1917–1923), Middle (1950–1972), and Contemporary (2015–2019). We then identified morphologically distinct clusters while remaining agnostic to species identifications. We found that morphological diversity and the number of distinct clusters declined over time. We then leveraged species identifications to highlight key species losses and examine morphological shifts among extant species. Our findings provide insights into the historical and contemporary morphological diversity of ciscoes and will inform restoration efforts.

First Record of Loppe's Tadpole Fish Ijimaia Loppei (Ateleopodidae) in the Gulf of Cadiz (SW Iberian Peninsula), Including Notes on its Diet

This paper reports the first record of a rare deep-sea fish Ijimaia loppei Roule, 1922 (Ateleopodiformes: Ateleopodidae) in the Southwest Iberian Peninsula, based on a single specimen (total length 1271 mm) bottom trawled in the mud volcano field in the Gulf of Cadiz, Spain (36º 28′ 54'' N, 7º 07′ 47'' W), at a depth of 585 m, on April 24, 2024. The morphometric and meristic measurements of I. loppei and its congener, I. antillarum, are presented and compared to previously published data. Further, this study provides insights into the diet of I. loppei and fills a gap in the known geographical distribution of the species, thereby contributing to the understanding of the ichthyofaunal biodiversity in the Gulf of Cadiz and establishing conservation strategies for habitats of ecological importance, such as the mud volcanoes.

Morphometric and Meristic Diversity in Eel (Anguilla bicolor) in South Coast of Java

Indonesia is the largest exporter of eel to consumer countries such as European, America, Taiwan, Japan, South Korea, and the Middle East. Eels are catadromous fish that are in the growth phase in fresh waters and the development phase is in marine waters. Meristic measurement is done by counting the spine (vertebrates). Eel morphometric measurements include TL (Total Length), HL (Head Length), PDL (Pre-Dorsal Length), PAL (Pre-Anal Length) and ADL (Ano-Dorsal Length). The purpose of this study was to analyze the morphological, morphometric, and meristic diversity of intraspecies between populations. Based on the research, the samples identified were morphologically almost the same between the populations, this was seen from the color patterns in the form of plain black or brown and short fins. The morphometric and meristic measurements in the 3D distribution plot still appear to be clustered in one population, while in the dendrogram clade, one species is still congregated in each. The results of the interpretation of the matrix plot of the lowest diversity are the length and number of anodorsal vertebrate segments. This observation can be concluded that the TL and TV of the eel varied, while the PDL, PAL, PDV, PAV, ADV showed the intraspecies character of A. bicolor. This is because the distribution of A. bicolor eels that inhabit the waters of Java Island is widely distributed and random (panmitic).

An overview of the taxonomic instability of endangered Golden and Zhobi mahseer in Pakistan.

In South and South East Asia three genera of fish species i.e. Tor, Neolissochilus and Naziritor are commonly known as Mahseer with at least 47 species. Among these 23 belongs to genus Tor, 22 to Neolissochilus and one to Naziritor i.e. Naziritor zhobensis. Recently another species added to genus Naziritor is Naziritor chelynoides in India. Among Tor species Tor putitora (Hamilton) is the most widely distributed Mahseer in Pakistan and other countries of the Indian subcontinent. However, based alone on morphological characters some authors identify the Pakistani counterparts as Tor macrolepis (Heckel), (a species presumed to be found exclusively in the Indus River system) distinct from Tor putitora (a species found in Ganga Brahmaputra River system). In order to resolve this taxonomic ambiguity, present study carried out meristic and morphometric measurements of Mahseer collected from a total of 11 water bodies of Pakistan. Ratios between the morphometric characters were calculated and statistically analyzed using t-test and correlation coefficient. Two species identified as Tor putitora and Naziritor zhobensis were the sole Mahseer inhabitants of Indus system in Pakistan. Tor putitora occurred at all surveyed sites while Nazirtor zhobensis had a distribution range from river Zhob to tributaries of river Gomal the right bank tributaries of River Indus. The study corroborates that there are no unequivocal morphological synapomorphies in any existing populations of both species. The study further demonstrates that head length, a character frequently used in Mahseer taxonomy, is not a good measure for species identification. Finally the present study establishes that Naziritor zhobensis still exists in the water bodies of Pakistan and that golden Mahseer occurring in Indus riverine system of Pakistan is Tor putitora.

Evaluation on the growth pattern and biological conditions of Sembilang (Plotosus canius) in East Aceh

Sembilang (Plotosus canius) is a delicious and nutritious fish that belongs to the family of Plotosidae and has great demand in coastal communities. Therefore, this research aimed to examine the data on growth patterns, morphometric and meristic measurements, and feeding habits of sembilang in the East Aceh mangrove area. The data collection included growth patterns, fish and fin length, and body width, and then the meristic measurements were carried out by counting the number of fin rays. The results showed that the length and weight of the fish ranged from 22-43 cm and 86-296 gr, respectively. Furthermore, the correlation coefficient r is 0.986 and the regression equation is W = 0.024L2.410. Its main diet is shrimp, with an IP rate of 47%, and they also consume feeds such as worms, small fish, crabs, and pieces of leaves. In conclusion, the growth pattern of sembilang (Plotosus canius) in the East Aceh mangrove area was negative allometric.

A taxonomic revision of Northeast Pacific softnose skates (Rajiformes: Arhynchobatidae: Bathyraja Ishiyama)

Softnose skates (Rajiformes: Arhynchobatidae: Bathyraja Ishiyama) are the most diverse skate genus, with 54 species, and are readily distinguishable from other genera in the family by their poorly calcified, flexible rostral cartilages. Six Bathyraja species are considered valid in the eastern North Pacific, including: B. abyssicola, B. aleutica, B. kincaidii, microtrachys, B. spinosissima, and B. trachura. Similar to other skate genera, eastern North Pacific Bathyraja lack a robust species-specific identification, which leads to issues with setting catch limits and creating management plans. This study identifies and formally redescribes the eastern North Pacific softnose skate species based on morphometric and meristic measurements and includes an Alaskan species, Bering Skate, B. interrupta due to its close morphological relationship to B. kincaidii. A lectotype for B. interrupta is designated. Multivariate tests determined that significant differences existed between the study species. Parsimonious phylogenetic trees showed that B kincaidii represents the basal condition, with B. abyssicola and B. aleutica being the most derived species in the study. The formerly synonymized species B. interrupta and B. kincaidii were shown to be separate, as were the previously synonymized species B. microtrachys and B. trachura. Improved Bathyraja species identification will hopefully assist fisheries managers in developing conservation policies easing the impacts of deep-sea fishing expansion.

Congochromis rotundiceps sp. nov., a new cichlid species (Actinopterygii: Cichlidae) from the Congo Drainage

A new dwarf cichlid, Congochromis rotundiceps sp. nov., (Cichliformes: Cichlidae) is described from the central Congo basin. It is a species of Congochromis based on the following characters: (1) four pores in the dentary laterosensory canal; (2) absence of a laterosensory canal in the angulo-articular, (3) six pores in the preopercle laterosensory canal; (4) a single tubular infraorbital bone behind the lachrymal; (5) 12 circumpeduncular scales; (6) jaw teeth comparatively robust, unicuspids, not closely spaced; and (7) presence of a small, supraneural bone. Congochromis rotundiceps sp. nov. is distinguished from all other Congochromis species by the combination of the following characters: (1) a larger eye diameter (31.435.1% HL), (2) a shorter snout length (29.832.7% HL), (3) a shorter upper lip length (29.232.0% HL), (4) a shorter lower lip length (26.233.6% HL), (5) a shorter lower lip width (27.731.2% HL), and (6) a shorter anal-fin length (15.316.97% SL). Diagnostic characters were extracted mainly from meristic counts and distance measurements from 326 chromidotilapiine cichlid specimens representing all chromidotilapiine genera and 40 described or undescribed species. The analysis of the complete meristic and distance measurements database allowed the diagnosis of C. rotundiceps sp. nov., but not for diagnostic separation of many other chromidotilapiine genera, species, and lineages. This result highlights the necessity to explore additional characters to elucidate chromidotilapiine cichlid taxonomy further.

A Morphometric Assessment of Non-indigenous Populations of Pterygoplichthys pardalis (Pisces, Loricariidae) in Jamaica

A morphometric investigation of suckermouth catfish specimens collected from the Upper and Lower Morass of Black River, St. Elizabeth, Jamaica was conducted between June 2007 and May 2008. Descriptions of 39 morphometric and 15 meristic measures are given. Taxonomic assessment through the application of dichotomous keys, photographic identification, and comparison with other morphometric work on similar species, identified the loricariid as Pterygoplichthys pardalis (Pisces, Loricariidae). Further analysis revealed that populations of P. pardalis in the Upper Morass have relatively longer heads, longer snouts, longer and deeper caudal penduncles, and deeper dorsal fins compared with individuals from the Lower Morass. Principal Component Analysis (PCA) showed no distinct groups of P. pardalis occurring throughout the Black River Basin. Both populations exhibited allometric growth and the relationships between length and weight in the P. pardalis populations were significant and linear.

The first record of the lessepsian migrant Pteragogus trispilus Randall 2013 (Osteichthyes: Labridae) off the Libyan coast, east Mediterranean Sea

The Red and Mediterranean seas are connected by the Suez Canal. Since its opening, the Canal has been regarded as a hotbed for invading alien species. During the lessepsian migration, species find their way into the Mediterranean waters and the opposite rarely happens. A single specimen of the Lessepsian migrant labrid fish was obtained at a depth of 20 m during a fishing field trip in Al-Bardi region near the Libyan-Egyptian border. The fish sample was transported to the laboratory (Marine Resources Department, Faculty of Natural Resources and Environmental Sciences, Tobruk University, Tobruk, Libya) and subjected to morphometric and meristic measurements to facilitate its identification. The scientific identification has verified that the caught fish is Pteragogus trispilus belonging to family Labridae. This is the first record of Pteragogus trispilus in the east Mediterranean Sea off the Libyan coast.

A Case of Mistaken Identity: Genetic and Morphological Evidence for the Presence of Redeye Bass in the Verde River, Arizona

Abstract We report genetic and morphological evidence for the presence of Redeye Bass Micropterus coosae, in the Verde River of Arizona, previously thought to be Smallmouth Bass Micropterus dolomieu. We performed meristic measurements on 15 individuals sampled from the Upper Verde River Wildlife Area, Yavapai County, Arizona. Meristic data for lateral line scales, scales above lateral line, and scales below lateral line were all consistent with Redeye Bass and not Smallmouth Bass. We analyzed mitochondrial and nuclear genetic data to determine whether one of the black bass (Genus Micropterus) species historically introduced to the Verde River was Redeye Bass and whether they persist in the system. We extracted DNA from fin clips of five individuals for phylogenetic analysis of the nicotinamide adenine dinucleotide + hydrogen (NADH) dehydrogenase subunit 2 (ND2) mitochondrial gene and for analysis of nuclear DNA using a diagnostic Single Nucleotide Polymorphism (SNP) panel. Results of the ND2 genetic sequencing and phylogenetic analysis indicated that these fish likely originated from native Redeye Bass stock from the Coosa River system of Alabama, Georgia, and Tennessee. Similarly, nuclear SNP data from the five individuals collected from the Verde River aligned with Redeye Bass reference genotypes based on STRUCTURE analysis. These results support the hypothesis that at least one of the introductions of black bass in Arizona's Verde River founded a previously unrecognized population of Redeye Bass. Further work is needed to determine the extent of the Redeye Bass presence in Arizona, whether Smallmouth Bass are also present in the Verde River system, and if hybridization of Redeye Bass and other black basses is occurring.

Morphometry, length-weight relationship and relative condition factor of red-toothed trigger fish, Odonus niger

Aim: The study aimed to investigate the morphometric and meristic measurements, length-weight relationship and relative condition factor of Odonus niger landed along coastal Karnataka. Methodology: The morphometric and meristic measurements, length-weight relationship and relative condition factor (Kn) of O. niger was studied for a period of eight months from August 2019 to March 2020. The different morphometric characters were subjected to statistical analysis. The length-weight relationship was analyzed for both the sexes (female and male) and combined data. Monthly relative condition factor was analyzed for both the sexes and for different size group. Results: A comparison of different morphometric measurements exhibited good extent of correlation indicating good extent of interdependence of these characters. Four out of eight morphometric characters are environmentally controlled and suggested wide range of zoogeographical distribution of O. niger. The length-weight relationship is indicated as W = 0.046 L2.565, W = 0.044 L2.589 and W = 0.047 L2.561 with coefficient of determination (r2) of 0.910, 0.913 and 0.910 for male, female and combined sexes, respectively. The 'b' values of both the sexes (male and female) exhibited negative allometric growth (p<0.05) and appeared to be leaner. There was no significant (p<0.05) variation for relative condition factor (Kn) among the months and size groups. However, little higher values were observed during November and February. Interpretation: The study fills the knowledge gap and support for developing a suitable management system for this fish species.

Morphological measurements, length weight relationship and relative condition factor (Kn) of Obtuse barracuda Sphyraena obtusata (Cuvier, 1829) from South-eastern Arabian Sea

The study investigated morphometric and meristic measurements, length-weight relationship (LWR) and relative condition factor (Kn) of the Sphyraena obtusata from south-eastern Arabian Sea from August 2019 to March 2020. Three hundred and fifty two specimens having a length and weight range of 16.5 – 30.1 cm and 29.54 – 155.20 g, respectively were analyzed for morphological measurements (13 morphometric and 11 meristic), LWR and relative condition factor. The maximum correlation were existed between standard length (r > 0.985), fork length (r > 0.979) and pre-dorsal length 1 (r > 0.942) among the various morphometric variables. A disparity in relative growth was noticed among the morphometric traits. The Regression coefficient b value clearly indicates that growth of all the morphometric characters were isometric in connection with the total length, except for pelvic length (negative allometric), body depth (positive allometric) and caudal depth (positive allometric) (p < 0.01). The length-weight relationship of the individual sexes (male, female) and pooled data is indicated as W = 0.02275 L2.6033, W = 0.01786 L2.6815 and W = 0.01945 L2.6541 having the value of coefficient of determination (r2) as 0.9566, 0.9696 and 0.9658, respectively. The ‘b’ values for both males and females divulge negative allometric growth (p < 0.05). There was no significant difference for the relative condition factor (Kn) among the months and size groups.

Range Extension of Northern Form Dolly Varden (&lt;i&gt;Salvelinus malma malma&lt;/i&gt;) to the Upper Arctic Red River Watershed, Northwest Territories, Canada

Northern form Dolly Varden is an anadromous char with significant ecological value found in high-gradient rivers of the Western Arctic. Because of declines in population abundance, Dolly Varden was recently designated as “Special Concern” under the federal Species at Risk Act. This species is also of great cultural and dietary significance to Indigenous Peoples of many communities in the Western Arctic; thus, expanding knowledge of the distribution, biology, and essential habitat is an important priority. We present results of a fisheries survey in the headwaters of the Arctic Red River, Northwest Territories, that focused on confirming the presence of Dolly Varden. Of 143 fish captured among 12 sampling locations, two were Arctic grayling (Thymallus arcticus), 33 were slimy sculpin (Cottus cognatus), and 108 were char identified using qualitative and quantitative morphological features. A subsample of 44 char voucher specimens were frozen whole and later identified using a linear discriminant function (LDF) based on meristic counts and morphological measurements, and a mitochondrial DNA genetic marker. LDF scores indicated that char collected in the Arctic Red River were northern form Dolly Varden. Genetic analysis showed that all but one char possessed mitochondrial DNA sequences common in northern form Dolly Varden from Canada. Our results confirm the presence of Dolly Varden in the Arctic Red River headwaters, extending the confirmed known distribution of this taxon in the Northwest Territories approximately 450 km south and 100 km east of previously delimited areas.

A Report on Introduced Amazon Sailfin Catfish, Pterygoplichthys pardalis in Gombak Basin, Selangor, with Notes on Two Body Patterns of the Species

Invasive introduced fish species are well known for their deleterious impacts on aquatic biodiversity and environment. This study provides the first report on the occurrence of introduced Amazon sailfin catfish, Pterygoplichthys pardalis from the Gombak basin, Selangor, Malaysia, where the suckermouth catfish, Hypostomus plecostomus and vermiculated sailfin catfish, Pterygoplichthys disjunctivus had been previously reported. Besides, selected morphometric and meristic measurements between P. pardalis and P. disjunctivus from the Pusu River, Gombak basin were compared. Moreover, we also described two body patterns of the P. pardalis collected from the river. The body pattern which does not fit entirely with the known characteristics of P. pardalis or P. disjunctivus is suspected to be a result of hybridization between both species, but deeper study should be conducted to confirm this claim.

Early development of the endemic dace Telestes karsticus (Leuciscidae, Cypriniformes) in a Dinaric karst stream in Croatia

Early development of the endemic dace Telestes karsticus is described in a Dinaric karst stream in Croatia. Larvae were acquired from successful rearing in an aquarium. Basic morphometric and meristic measures of larvae were taken during 55 days of observation. The mean total length of larvae at the time of hatching was 6.45 mm. The yolk sac was completely absorbed in all larvae by day 9 post-hatching (PH), when the mouth also opened and independent feeding and intestinal function were observed. Flexion of the urostyle was completed between days 12–16 PH. The caudal fin became completely forked on day 23 PH. Formation of fin rays was complete on day 48 PH when fish fully resembled juvenile specimens. The number of soft ray fins corresponds to the adult. Understanding the early development is particularly valuable in assessing environmental impacts and recovering of this endangered species and it is essential for effective monitoring and its conservation. This is the first report of the early development for the endemic Telestes karsticus, pointing out the importance of the obtained results for the effective conservation of the species.

Some reproductive and biometric features of the endangered Gangetic Leaf Fish, Nandus nandus (Hamilton, 1822): Implication to the baor fisheries management in Bangladesh

This study reflects the biometric characters of the endangered species Nandus nandus (Hamilton, 1822) including sex ratio, length-length relationships (LLRs), and length-weight relationships (LWRs) utilizing the sum of 14 linear variables, various meristic measurements, reproductive biology, and condition factor from the Borni Baor, a large wetland ecosystem of southwestern Bangladesh. A total of 579 specimens of N. nandus have been periodically collected from the Borni Baor throughout the year (January–December, 2019) using different traditional fishing gears. Highly significant LLRs (r2 > 0.90) values indicate that length parameters are profoundly associated with one another. In the LWR formula (W = aLb), higher exponent b values (b > 3.0) were demonstrating a positive allometric growth with a high correlation coefficient (r2 > 0.94). Moreover, monthly gonadosomatic index and dobriyal index fluctuations suggest the primary breeding season of this fish is from March to July. Data revealed the breeding time was associated strongly with the rainfall and air temperature (p < 0.05). The results of our study exposed a cutting-edge biometric feature of this endangered species that would be applicable for fish stock evaluation and making management strategies and conservation policy for this valuable fish resource.

Confirmed Occurrence of Mola mola (Linnaeus, 1758) from Mersin Bay (Northeastern Mediterranean)

In June 2018, a single female specimen of the Ocean sunfish, Mola mola (Linnaeus, 1758) (122 cm in total length and 80 kg in weight) was caught by a commercial trammel net at a depth of 393 m in Mersin Bay (Bozyazi coast), Turkey. This paper presents the first substantiated occurrence and hence, the confirmation of M. mola in the Northeastern Mediterranean, Turkey. Morphological and meristic measurements of the specimen were made and recorded with the catalog number MEUFC-18-11-101 in the Museum of the Systematic in, Mersin University’s Faculty of Fisheries. Morphometric and meristic data matched other recordings of this species from parts of the Mediterranean, and the historical captured record of the species in the Mediterranean was documented.

Morphometric and meristic of an endemic fish Lagusia micracanthus bleeker 1860 from Ompo river, South Sulawesi

Lagusia micracanthus is an endemic freshwater fish species of South Sulawesi, Indonesia. The present study performs morphometric characteristics and meristic counts to L. micracanthus inhabiting Ompo River, South Sulawesi. Fishes were collected from the Ompo River in April 2018. Morphometric and meristic measurements were performed by following methods of Vari (1978), Vari & Hutchins (1978) and Shelley et al. (2017). Other additional measurements were based on Hubbs & Lagler (1974). Statistical analysis such as regression equation and correlation coefficient was following method of Brraich and Akhter (2015). An amount of 31 morphometric characters and 9 meristic counts were recorded from 30 fishes. Analysis of correlation on morphometric characters demonstrates six characters with high correlation coefficient, eighteen characters with moderate coefficient, and six characters with low coefficient.

Snakes of Şanlıurfa Province

In this study, a total of 170 specimens belonging to 21 snake species that have been collected from Şanliurfa province between 2016 and 2017 as well as during the previous years (2004-2015) and preserved in ZMADYU (Zoology Museum of Adiyaman University) were examined. Nine of the specimens examined were belong to Typhlopidae, 17 to Leptotyphlopidae, 9 to Boidae, 112 to Colubridae, 14 Natricidae, 4 Psammophiidae, 1 to Elapidae, and 5 to Viperidae families. As a result of the field studies, Satunin's Black-Headed Dwarf Snake, Rhynchocalamus satunini (Nikolsky, 1899) was reported for the first time from Şanliurfa province. The specimen belonging to Zamenis hohenackeri (Strauch, 1873) given in the literature could not be observed during this study. The color-pattern and some metric and meristic measurements of the specimens were taken. In addition, ecological and biological information has been given on the species observed.

Morphometric and DNA Barcoding of endemic Halmaheran walking shark (Hemiscyllium halmahera, Allen, 2013) in North Maluku, Indonesia

Abstract. Madduppa H, Putri ASP, Wicaksono RZ, Subhan B, Akbar N, Ismail F, Arafat D, Prabuning D, Sani LMI, Srimariana ES, Baksir A, Bengen DG. 2020. Morphometric and DNA Barcoding of endemic Halmaheran walking shark (Hemiscyllium halmahera, Allen, 2013) in North Maluku, Indonesia. Biodiversitas 21: 3331-3343. The walking shark (Hemiscyllium halmahera) commonly referred to as bamboo shark, is a shark species that belongs to the Hemiscyllidae family which is endemic in North Maluku, and Indonesian waters. These Hemiscyllium species are generally confined to the Australian-New Guinea region, save a specie which originates from Halmahera, an Indonesian island. Ever since its discovery, sufficient information on its existence has been largely unavailable. Hence, the purpose of this study is (1) to assess the morphology, using meristic measurements and length-weight relationship, and (2) to determine the molecular characteristics through DNA barcoding, phylogenetic reconstruction, and genetic diversity. The samples used in this research were obtained from Halmahera Archipelago, North Maluku, including Halmahera, Tidore, Ternate, Maitara, and Guraici in several expeditions between March 2017 and January 2018. 36 individuals in total were measured for morphometric parameters including Total Length (TL), Standard Length (SL), Head Length (HL), Body Circumference (BC), and Body Weight (BW). Out of a total of 36 sharks, tissue samples were obtained from 32 individuals for molecular identification. After the required measurements were obtained, all individuals sharks were released back to their habitat safely. Equations of linear regression were used to analyze the relationship between length and weight. Morphometric measurements indicated that the average total length of the walking shark samples obtained, were not more than 75± cm for both male and female specimens. The length-weight analysis revealed a positive allometric growth pattern in H. halmahera species, where weight was gained faster than an increase in length. The results of the DNA fragment length analysis from all samples were 793-bp. All 32 tissue samples identified as H. halmahera consisted of 3 samples from Ternate Island, 14 samples from Maitara Island, 9 samples from Guraici Island (South Halmahera), 10 samples from Central Halmahera, and 2 samples from Tidore Island. These results confirmed that DNA subsequence analysis indicates that H. halmahera is different from those sequences extracted from Genbank in the Australia-New Guinea region. This study successfully identified H. halmahera based on their morphological and molecular characters, and has therefore contributed to international genetic database (Barcoding Of Life Database-BOLD) for further studies.