Pharyngeal Teeth Research Articles

Distribution and Some Diagnostic Properties of Capoeta damascina (Valenciennes, 1842) in Streams of the Ceyhan and Seyhan River Basins, Türkiye

This study determined the distribution and some diagnostic characteristics of Capoeta damascina, which belongs to the Cyprinidae family, in the Ceyhan and Seyhan River basins. C. damascina individuals were detected in 21 of 25 Ceyhan River Basin stations and 12 out of 15 in the Seyhan River basin stations. C. damascina show a wide distribution in the Ceyhan and Seyhan River basins. It has been determined that C. damascina lives at altitudes between 125 m (Hemite Stream) and 1620 m (Söğütlü Stream) in the Ceyhan River basins, and in streams at altitudes ranging from 165 m (Çakıt stream) to 1758 m (Sarız Stream) in the Seyhan River basins. The average total length of C. damascina individuals (n: 218) caught in the Ceyhan River Basin is 14.72 cm, and their average weight is 40.12 g. In the Seyhan River basin, the average total length of C. damascina individuals (n: 74) was found to be 17.31 cm, and their average weight was 72.24 g. The mean number of line lateral scales was 71, the number of gill rakers was 23, and the number of pharyngeal teeth was 4:3:2-2:3:4.

The feeding ecology of grass carp: A review

AbstractAs an economically important herbivorous fish, the range of grass carp (Ctenopharyngodon idella) has expanded in the world and its ecological influences have become more evident. Currently, we have embarked on assessing the effect of grass carp on aquatic organisms and water quality by integrating the outcomes from previous ecological studies. Bibliographical data integration shows that aquatic plant preference is likely to be related to the cellulose proportion, calcium, sucrose and citric acid of the aquatic plant. Moreover, pharyngeal teeth and multiple gene copies of taste receptors could help reveal the feeding mechanism of grass carp. The expansion of the number of sweet‐detecting T1R2 genes, and the functional potential of Umami taste receptor T1R3 by calcium‐regulation was speculated on the basis of previous experimental observations of grass carp, suggesting that aquatic plant consumption by this species is tightly associated with the taste receptors. Apart from the competition in living space between grass carp and other fish, the effects of consuming zooplankton and zoobenthos were summarized to reveal general passive feeding of grass carp, as well as the feeding choice in the absence of aquatic plants. Water quality data were gleaned to make comparative analyses between groups stocking with and without grass carp to uncover changes in water physicochemical parameters in short‐ (<1 year) and long‐term impacts. This review provides insight into the grass carp feeding behaviour and mechanisms and it will help find a balance between ecological harmony and the industrial development of grass carp.

Ultrastructure of the Oropharyngeal Cavity Floor of the Red Porgy (Pagrus pagrus) by Light and Scanning Electron Microscopy

Abstract The current research aim is an ultrastructural examination of the floor of the oropharyngeal cavity of the red porgy fish. The study used gross morphology, light and scanning electron microscopy, and morphometric analysis. The teeth are arranged in anterior and posterior rows with differing heights along the entire length of the lower jaw. The labial teeth were long papilliform (canine like), medium, and short papilliform teeth. The teeth had a central pulp cavity and were surrounded by a thick dentine ridge covered in enamel. The pharyngeal teeth appeared in a V-shaped structure after the end of the interbranchial septum. There were three sizes of pharyngeal teeth: long, medium, and short. The apical pouch appeared on the lateral sides of the tongue. The tongue had a bulged mountaintop in the center and lateral sides with sea-wave-like longitudinal ridges with sloping grooves between them. The whole tongue surface had longitudinal ridges and sharp transverse ridges that appeared thorn like at the tongue root. Many sizes of pointed papillae were visible along the tongue surface. Ruffini corpuscles have been discovered in the tongue’s conical and dome-shaped papillae. The red porgy’s teeth and tongue papillae have distinct structural characteristics that are reflected in their carnivorous behavior.

Late Mesolithic Individuals of the Danube Iron Gates Origin on the Dnipro River Rapids (Ukraine)? Archaeological and Bioarchaeological Records

Abstract In contrast to large-scale prehistoric migrations, associated with massive population shifts and changes in material culture, movements of small human groups or single individuals are barely visible but no less important. In publications of the 1960s–2000s, specificity of craniological, odontological, and metrical characteristics as well as stable isotope values of some individuals distinguishing the Late Mesolithic cemetery of Vasylivka II among other Mesolithic and Neolithic burial sites in the Dnipro River basin was explained by some gene flows. However, archaeologists could not develop these views since the original excavation report of 1953 and all grave goods from Vasylivka II were considered lost. Another old field document, where pendants of the pharyngeal teeth of fish, and the shells of spiral, probably Mediterranean, molluscs found there were mentioned, allowed the recent suggestion of the author of the current article that several individuals from the Danube Iron Gates region were interred in the cemetery. Previous arguments along with new evidence are presented here to develop this hypothesis. Re-found personal ornaments from one burial, the only available grave goods from Vasylivka II, are published here for the first time. The established regularity that most relatively young men and women from the graveyard have conditional “Danubian” δ13C values in the range from −20 to −21‰ assumes the mutual exchange of marriage partners born in the Iron Gates and the Dnipro Rapids. A waterborne route is discussed as a more probable mode of communication between these regions.

Palynological recovery of small carbonaceous fossils (SCFs) indicates that the late Cambrian acritarch Goniomorpha Yin 1986 represents the teeth of a priapulid worm

New palynological studies from the Xiaoyangqiao section (Jilin Province, north-east China), which has been selected as an Auxiliary Boundary Stratigraphic Section and Point (ASSP) for the base of the Ordovician, confirms the presence of Goniomorpha Yin 1986 in intervals ranging from the late Cambrian (Furongian) to the Early Ordovician (Tremadocian), and allow us to clarify its morphology and affinities. Despite being compared originally to vesicular microfossils with processes arising from one pole, Goniomorpha lacks an enclosed cavity, so it cannot be classified as an acritarch in the strict sense. Instead, we find that the specimens originally described as Goniomorpha are actually part of a wider spectrum of morphologies that are identifiable as the pharyngeal teeth of priapulid worms. The best-preserved specimens resolve the ‘processes’ as denticles arising from an arch on the margins of a cuticular pad, sometimes with an extending spur and polygonal microstructure. Closely equivalent forms have been reported from Cambrian assemblages of small carbonaceous fossils (SCFs) and in situ on Burgess Shale specimens of the priapulid Ottoia. The findings from the Xiaoyangqiao section extend the taphonomic range of Cambrian-type SCFs into the Ordovician, and provide the first evidence for priapulids from the Ordovician of northern China. More generally, our results demonstrate the reciprocal insights from palynological and SCF-type processing for identifying problematic microfossils.

Özlüce Baraj Gölü (Elazığ-Bingöl, Türkiye)’nde yaşayan Alburnus sellal Heckel, 1843 Populasyonunda Bazı Morfometrik ve Meristik Özelliklerinin İncelenmesi

Bu çalışmada, ana akarsuyu Peri Çayı olan Özlüce Baraj Gölü’nden yakalanan Alburnus sellal Heckel, 1843 türüne ait bireylerde bazı morfometrik ve meristik özelliklerinin belirlenmesi amaçlanmıştır. 135 adet A. sellal bireylerinde bazı morfometrik özellikler ile birbirlerine olan oranları ortalama, maksimum, minimum, standart sapma, standart hata ve varyasyon katsayısı olarak hesaplanmıştır. Ayrıca bazı vücut ölçümlerinin standart boyda oranları (%) ile regresyon denklemleri ve korelasyon katsayıları hesaplanmış olup pozitif yönde kuvvetli ilişkiler olduğu belirlenmiştir. Meristik özelliklerden, yanal çizgi (80-88) ve transversal yöndeki pul sayıları (13-17/5-7), yüzgeçlerdeki basit ve yumuşak ışın sayıları (dorsal III/8-9, ventral I-II/8-9, pektoral I/14-17, anal III/11-15), solungaç diken sayıları (13-18), farinks diş sıra ve sayıları (2.5-5.2) belirlenerek, türe ait tanımlayıcı özellikler belirlenmiştir.

Evidence for the cooking of fish 780,000 years ago at Gesher Benot Ya'aqov, Israel.

Although cooking is regarded as a key element in the evolutionary success of the genus Homo, impacting various biological and social aspects, when intentional cooking first began remains unknown. The early Middle Pleistocene site of Gesher Benot Ya'aqov, Israel (marine isotope stages 18-20; ~0.78 million years ago), has preserved evidence of hearth-related hominin activities and large numbers of freshwater fish remains (>40,000). A taphonomic study and isotopic analyses revealed significant differences between the characteristics of the fish bone assemblages recovered in eight sequential archaeological horizons of Area B (Layer II-6 levels 1-7) and natural fish bone assemblages (identified in Area A). Gesher Benot Ya'aqov archaeological horizons II-6 L1-7 exhibited low fish species richness, with a clear preference for two species of large Cyprinidae (Luciobarbus longiceps and Carasobarbus canis) and the almost total absence of fish bones in contrast to the richness of pharyngeal teeth (>95%). Most of the pharyngeal teeth recovered in archaeological horizons II-6 L1-7 were spatially associated with 'phantom' hearths (clusters of burnt flint microartifacts). Size-strain analysis using X-ray powder diffraction provided evidence that these teeth had been exposed to low temperature (<500 °C), suggesting, together with the archaeological and taphonomic data, that the fish from the archaeological horizons of Area B had been cooked and consumed on site. This is the earliest evidence of cooking by hominins.

Morphology of larval and postlarval stages of Priapulopsis bicaudatus (Danielssen, 1869) (Priapulida) from the north atlantic ocean

We investigated larvae, postlarval stages and one adult of the priapulid Priapulopsis bicaudatus (Danielssen, 1869) collected in different locations in the North Atlantic between 300 and 1000 m depth. The superficial sculpture of the lorica of larvae remains unchanged in the stages investigated. We confirm the presence of frontal and laterofrontal lorica plates and the presence of first ring pharyngeal teeth with a distinct bipartition on one side. In postlarval stages, the separation of one first ring tooth into two parts could be demonstrated. All observed teeth possess receptors called tooth receptors. The paired caudal appendage, characteristic for the species, grows asymmetrically during early development. Ringpapillae appear late in development. The scalid arrangement basically corresponds between larvae and postlarval stages and can be generalized for priapulids. Additionally, scalids anterior of the primary scalids are reported in postlarval stages.

Micro-morphological characteristics of the oropharyngeal cavity floor of bogue (Boops boops) (Linnaeus, 1758) fish: gross morphology, light, and scanning electron microscopic imaging

The current study is the first to use gross anatomy, light, and scanning electron microscopy to describe the oropharyngeal cavity of a bogue (Boops boops Linnaeus, 1758) fish. Fourteen 17–18 cm long bogue fish were used. The lower jaw held the lower lip, labial teeth, tongue, and pharyngeal teeth, and the oral cavity floor appeared u-shaped. The lower jaw was small and narrow in the anterior and wide in the posterior as it approached the esophagus. The lower lip carried different lengths of cilia-like projections that looked like the cactus plant arranged in transverse layers, and its apex appeared as an open rose. These cilia were encircled by ridges that looked like sea waves. The labial teeth were 15 in a row, with long roots placed beneath a pocket-like structure. Long, medium, and short pharyngeal papilliform teeth emerged on the oropharyngeal cavity floor at the level of the fourth gill arch in a small V-shaped arrangement. The tongue was smooth and small, with an apex, body, root, and lateral edges that were all clearly defined. The tongue’s apex was pointed and triangular, with a thin, transparent apical pouch around it. There was a median longitudinal fold on the dorsum of the tongue body and root. On the tongue surface, taste bud types I and II emerged. The bogue fish’s oropharyngeal cavity had unique anatomical characteristics, indicating that it was omnivorous.

Comparative analysis of growth performance, pharyngeal teeth and intestinal traits in F1 hybrids of female Megalobrama amblycephala × male Culter mongolicus

Aquaculture provides approximately 78% of the fish consumed by humans in China. However, the characters of fish cultivars have different deficiencies, and degradation is serious. Less improved varieties of fish are still an important factor restricting the development of aquaculture in China. Interspecific hybridization is an effective method for producing hybrid varieties with desirable traits. In this study, diploid hybrids (BM, 2n = 48) of blunt snout bream (Megalobrama amblycephala ♀, 2n = 48, BSB) × Mongolian culter (Culter mongolicus ♂, MC, 2n = 48) were obtained by intergeneric crossing. To investigate whether these hybrids have heterobeltiosis, the growth performance, pharyngeal teeth and intestinal traits of BM hybrids were compared with those of their parents (BSB and MC). The average weight of BM hybrids (97.01 ± 27.52 g) was significantly greater (P < 0.05) than that of MC (68.04 ± 12.64 g) and similar to that of BSB (99.33 ± 16.72 g) at 1 year of age; the average weight of BM hybrids (990.49 ± 149.21 g) was significantly greater (P < 0.05) than that of both BSB (895.12 ± 135.38 g) and MC (625.81 ± 81.83 g) at 2 years of age. The pharyngeal tooth structure and intestinal traits of BM hybrids were similar to those of BSB, indicating that BM hybrids were biased toward herbivory. This is the first report of a diploid hybrid with a growth advantage and herbivory produced by crossing female BSB and male MC. The new hybrid offspring have great significance in aquatic applications.

Spatiotemporal characteristics of the pharyngeal teeth in interspecific distant hybrids of cyprinid fish: Phylogeny and expression of the initiation marker genes.

As an important feeding organ and taxonomical characteristic, the pharyngeal teeth of cyprinid fish have very high morphological diversity and exhibit species-specific numbers and arrangements. Many genes have been verified to regulate the pharyngeal teeth development and act as the initiation marker for teeth. Six initiation marker genes for pharyngeal teeth were used as RNA probes to investigate the expression pattern, and these genes were further used to construct a phylogenetic tree for cyprinid fish including some distant hybrids. The results from in situ hybridization showed that similarities and differences existed in the expression of dlx2b, dlx4b, dlx5a, pitx2, fth1b, and scpp5 in the pharyngeal region of the hybrids (BT) by the crosses of blunt snout bream (BSB, ♀) × topmouth culter (TC, ♂). Particularly, we found a high specificity marker gene scpp5 for the early development of pharyngeal teeth. The Scpp5 expression pattern established a clear graphic representation on the spatiotemporal characteristics of the early morphogenesis of pharyngeal teeth in BT and BSB. Our results suggested that the scpp5 expression in 4V1, 3V1, and 5V1 in BT occurred earlier than that in BSB, while the replacement rate of pharyngeal teeth (4V2, 3V2, and 5V2) was faster in BSB. Phylogenetic analysis revealed that the six marker genes were highly conserved and could be used as the molecular marker for identifying the parents of the distant hybrids in cyprinid fish. The expression patterns of the scpp5 gene was examined in various tissues, including the brain, gill, heart, liver, muscle, skin, fins, gonad, eye, and kidney, showing that the scpp5 gene was ubiquitously expressed, indicating its important role in cyprinid fish.

Dental structure and tooth attachment modes in the common fangtooth Anoplogaster cornuta (Valenciennes, 1833) (Actinopterygii; Trachichthyiformes; Anoplogastridae).

We studied the structure and attachment modes of the teeth of adult Anoplogaster cornuta using light- and scanning-electron microscopic techniques. All teeth were monocuspid, composed solely of orthodentin, and lacked a covering enameloid cap. Fourteen teeth were present in the oral jaws, with three teeth each on the left and right premaxilla and four teeth each on the left and right dentary. The anteriormost premaxillary and dentary teeth were considerably larger than the more posteriorly located ones. The oral jaw teeth were transparent, non-depressible and firmly ankylosed to their respective dentigerous bone by a largely anosteocytic bone of attachment. No evidence for replacement of the large oral jaw teeth was found in the analyzed adult specimens. The bone of attachment exhibited lower calcium and phosphorus concentrations and a higher Ca/P ratio than the orthodentin. The connection between dentinal tooth shaft and bone of attachment was stabilized by a collar of mineralized collagen fibers. In contrast to the oral jaw teeth, the pharyngeal teeth exhibited a ring-like fibrous attachment to their supporting bones. This mode of attachment provides the teeth with some lateral mobility and allows their depression relative to their supporting bones, which may facilitate intra-pharyngeal prey transport. In contrast, a firm ankylosis was observed in numerous small teeth located on the branchial arches. The function of these teeth is presumably to increase the tightness of the pharyngeal basket and thereby the retention of small prey items in a species living in a habitat with only sparse food supply. Our findings corroborate earlier statements on the tooth attachment modes of the oral jaw teeth of Anoplogaster cornuta, but provide new findings for the attachment modes of pharyngeal teeth in this species.

Influence of hook type on performance, hooking location, injury, and reflex action mortality predictors in float recreational angling for cyprinids: A case study in northeastern Poland

One of the elements critical to the success of catch-and-release fisheries is the use of appropriate gear that permits releasing fish safely. To date, not all fish species have been the focus of comprehensive studies on this topic, and this applies to cyprinids. Fish from this family are distinct because of their pharyngeal teeth and the particular way they ingest food. We evaluated the impact of hook type on cyprinid catch rates (further catch per unit effort (CPUE)), the size of the fish caught, and the welfare of the fish released. Quickly assessing immediate reactions with reflex action mortality predictors (RAMP), we determined the consequences of recreational angling with barbed J-hooks, barbless J-hooks, and circle hooks. During the study, 1,066 fish were caught that belonged to eight native cyprinid species. Hook type did not have a significant impact on the fishing index with the mean CPUE ranging from 14.4 (circle hook) to 17.2 (barbed J-hook). The size of the fish caught also did not depend on hook type. However, hook type influenced the efficiency of hook removal, which was the lowest for circle hooks (45.6 %) and the highest for barbless hooks (63.7 %). Dehooking time was linked significantly with hook type, hook location, and fish species. The longest dehooking time was noted for fish caught with barbed J-hooks. Anatomical hooking locations did not differ in the fish caught with J-hooks, while the hooking location of circle hooks differed significantly in comparison to that of the J-hooks. Deep hooking in fish caught with circle hooks occurred decidedly less frequently as did tissue damage. Bleeding occurred more frequently in fish that exhibited impaired reflex action mortality predictors. Fish caught with circle hooks exhibited the least impaired reflexes. The differences in the build of the anterior part of the cyprinid digestive system and the manner in which theses fishes take up food did not exclude using circle hooks.

Improved genome assembly of Chinese sucker (Myxocyprinus asiaticus) provides insights into the identification and characterization of pharyngeal teeth related maker genes in Cyprinoidei

The Chinese sucker, Myxocyprinus asiaticus (M. asiaticus, Catostomidae, Cypriniformes), is the only living species of Catostomidae in Asia. There are more than 75 species of this family in North America. The fossil record of this group dates back to the early Eocene. As the Chinese sucker is located at the base of the Cyprinoidei phylogeny, this species is also important in clarifying the evolutionary relationships within Cyprinoidei. Here, we assembled a high-quality genome of the Chinese sucker, contig N50 (40.26 ​Mb), which is nearly ten times longer than the previous version (4.19 ​Mb). Phylogenetic analysis identified that Chinese sucker together with Cyprinidae groups are paraphyletic with respect to Cobitoidea. The specific whole genome duplication event of the Chinese sucker was estimated to have occurred ∼25.9 million years ago. Analysis of population historical changes indicated a trend of reduction for the Chinese sucker and T. tibetana. Since Dlx genes play a key role in Cypriniformes pharyngeal teeth development, we conducted a genome-wide identification of Dlx genes, and found that these genes were doubled in whole genome duplication events, followed by the loss of specific copies. Transcriptome results showed that the expression levels of these paralogous genes were similar. This genomic resource provides useful information for the protection of Chinese sucker and functional study of Dlx genes.

Geometric morphometric comparison of the oral jaw and lower pharyngeal jaw of the closely-related cichlid, Vieja bifasciata, V. breidohri and V. hartwegi (Cichliformes: Cichlidae)

Systematics of the genus Vieja is complex, with many morphologically similar species that have little genetic differentiation. Examination of additional morphological traits can be useful for clarifying their taxonomic status and evolutionary history. We analyzed morphological variation of bones in the oral jaw and lower pharyngeal jaw to determine if these structures permit delimitation of species and to study possible functional implications. Morphological differences were quantified from canonical variates analysis, MANOVA, and paired comparisons. Differences in the number of pharyngeal teeth in the lower pharyngeal jaw were determined using an ANCOVA. The shape of the premaxilla and lower pharyngeal jaw are best for differentiating between these closely related-species. Although the morphological variation between V. breidohri and V. hartwegi were most similar, the shape of the lower pharyngeal jaw contrasts in morphospace. Vieja bifasciata possesses more teeth in the lower pharyngeal jaw. Variation in this bones may effect jaw biomechanics. Morphological differences are in contrast with the little genetic differentiation observed. The geographic isolation of V. bifasciata is likely related to its morphological differentiation. The common ancestry of V. breidohri and V. hartwegi probably explains their small morphological divergence.

Phylogeographic relationships and the evolutionary history of the Carassius auratus complex with a newly born homodiploid raw fish (2nNCRC)

BackgroundAn important aspect of studying evolution is to understand how new species are formed and their uniqueness is maintained. Hybridization can lead to the formation of new species through reorganization of the adaptive system and significant changes in phenotype. Interestingly, eight stable strains of 2nNCRC derived from interspecies hybridization have been established in our laboratory. To examine the phylogeographical pattern of the widely distributed genus Carassius across Eurasia and investigate the possible homoploid hybrid origin of the Carassius auratus complex lineage in light of past climatic events, the mitochondrial genome (mtDNA) and one nuclear DNA were used to reconstruct the phylogenetic relationship between the C. auratus complex and 2nNCRC and to assess how demographic history, dispersal and barriers to gene flow have led to the current distribution of the C. auratus complex.ResultsAs expected, 2nNCRC had a very close relationship with the C. auratus complex and similar morphological characteristics to those of the C. auratus complex, which is genetically distinct from the other three species of Carassius. The estimation of divergence time and ancestral state demonstrated that the C. auratus complex possibly originated from the Yangtze River basin in China. There were seven sublineages of the C. auratus complex across Eurasia and at least four mtDNA lineages endemic to particular geographical regions in China. The primary colonization route from China to Mongolia and the Far East (Russia) occurred during the Late Pliocene, and the diversification of other sublineages of the C. auratus complex specifically coincided with the interglacial stage during the Early and Mid-Pleistocene in China.ConclusionOur results support the origin of the C. auratus complex in China, and its wide distribution across Eurasia was mainly due to natural Pleistocene dispersal and recent anthropogenic translocation. The sympatric distribution of the ancestral area for both parents of 2nNCRC and the C. auratus complex, as well as the significant changes in the structure of pharyngeal teeth and morphological characteristics between 2nNCRC and its parents, imply that homoploid hybrid speciation (HHS) for C. auratus could likely have occurred in nature. The diversification pattern indicated an independent evolutionary history of the C. auratus complex, which was not separated from the most recent common ancestor of C. carassius or C. cuvieri. Considering that the paleoclimate oscillation and the development of an eastward-flowing drainage system during the Pliocene and Pleistocene in China provided an opportunity for hybridization between divergent lineages, the formation of 2nNCRC in our laboratory could be a good candidate for explaining the HHS of C. auratus in nature.

Colorimetric and fluorescent TRAP assays for visualising and quantifying fish osteoclast activity.

Histochemical detection of tartrate-resistant acid phosphatase (TRAP) activity is a fundamental technique for visualizing osteoclastic bone resorption and assessing osteoclast activity status in tissues. This approach has mostly employed colorimetric detection, which has limited quantification of activity in situ and co-labelling with other skeletal markers. Here, we report simple colorimetric and fluorescent TRAP assays in zebrafish and medaka, two important model organisms for investigating the pathogenesis of bone disorders. We show fluorescent TRAP staining, utilising the ELF97 substrate, is a rapid, robust, and stable system to visualise and quantify osteoclast activity in zebrafish, and is compatible with other fluorescence stains, transgenic lines and antibody approaches. Using this approach, we show that TRAP activity is predominantly found around the base of the zebrafish pharyngeal teeth, where osteoclast activity state appears to be heterogeneous.

New record and first description including SEM and μCT of the rare priapulid Acanthopriapulus horridus (Priapulida, Scalidophora)

We report a specimen of the rare priapulid Acanthopriapulus horridus from the Magellan Strait in Chile. This species, characterized by a conspicuous spine-covered caudal appendage, is distributed along the South American coast from Rio de Janeiro (Brazil) to the Magellan Strait, but only six specimens have been reported so far. This is the first documentation using scanning electron microscopy (SEM) and μCT. Our investigation confirms and extends most reported results from previous publications. We show that the scalids on the introvert, although more loosely arranged than in other priapulids, occur in repeated series of decreasing size. Scalids and the different papillae on the trunk are sensory structures with apical tube-like openings. The spines on the caudal appendage have an apical opening, but pores instead of tube-like receptor openings. Pharyngeal teeth appear to be of two types in different regions of the pharynx. The caudal appendage is a strongly muscular organ, but its function remains unclear.

Morphology and morphometry of pharyngeal bone and teeth in cyprinid species from the Kurdistan Region, Iraq

The morphology of pharyngeal bones and teeth was determined on seven cyprinid species caught from the Greater Zab River, a tributary of Tigris River, located in the northern part of Iraq in the Kurdistan Region. Eleven morphological characters of the pharyngeal bone and teeth were identified, measured and compared from photographs of the 152 individual species collected. The relationship between pharyngeal bone total length and four-dimensional measurements of the pharyngeal bone were determined using linear regression and multivariate analysis. Results show bone characteristics of the studied species are distinctly different in terms of shape, tooth number, tooth formulae and dimensions of the pharyngeal bones. Regression analysis shows positive coefficients of TL with all parameters PL, DL, PW and DP while multivariate linear discriminate analysis shows distinct groupings of each species using non-dimensional measurements of the bone characters. The measurements gathered and application of biometric relationships to ease the identification of the cyprinid species contributes to the morphological information on cyprinid species in a data deficient region of the world. This work provides a new set of morphological characters of the pharyngeal bone and teeth of the seven cyprinid species from Northern Mesopotamia that may enable their separation from the members of their cyprinid genera.

Investigations into Early Larval Feeding Practices for the Tiger Barb Puntigrus tetrazona

AbstractThe Tiger Barb Puntigrus tetrazona is one of the highest trade volume freshwater species in the ornamental fish industry. Culture of larval Tiger Barb is largely dependent on live feeds at first feeding and throughout early life stages, leading to increased cost relative to the use of commercially produced microparticulate diets (MDs). Potential for the successful culture of Tiger Barb by using MDs from first feeding was evaluated here, with a focus on the physiological characteristics that limit digestive capacity in larval cyprinids, as well as the hypothetical benefit of including feed attractants in formulated larval feeds. Comparable growth and survival were achieved for the first 14 d of feeding with one of three MDs when compared to feeding with brine shrimp Artemia spp. Histological preparation revealed evidence for a fully functional pharyngeal jaw structure, including pharyngeal teeth and a pharyngeal pad, from 6 d posthatch, which coincided with first feeding. The masticatory function of these structures likely facilitated the breakdown and subsequent utilization of the relatively complex macronutrients that are characteristic of MDs. Inclusion of top‐coated potential attractants (tryptophan, taurine, trimethylglycine betaine, or a mix of the three) with the most successful MD from the original trial failed to induce an increased feeding response, as evidenced by the observation of similar feeding incidence, total larval protein content, and tryptic enzyme activity relative to a negative control MD without added attractants. The results of this research suggest that the successful culture of larval Tiger Barb is possible with the use of commercially available MDs, potentially leading to cost savings and increased resilience of producers in the ornamental aquaculture industry.