Mitochondrial 16S rDNA Sequences Research Articles

Systematic revision of the eastern Queensland land snail genus Figuladra Köhler and Bouchet, 2020 based on mitochondrial phylogenetics and comparative morpho-anatomy (Eupulmonata, Camaenidae)

ABSTRACT The current study revises the systematic taxonomy of Figuladra, a genus of camaenid land snails endemic to eastern Queensland, based on the investigation of many recently collected ethanol-preserved samples as well as historic museum material, including types. We employed comparative analyses to investigate the variation in morphological features (shell, penial anatomy) and performed phylogenetic analyses of mitochondrial 16S rDNA sequences to test species hypotheses. Phylogenetic analyses recovered three principal mitochondrial clades, one occurring in mid-east Queensland, one in south-east Queensland, and another in the upland areas of south-east Queensland. We recognise altogether 15 accepted species, including four that are newly described herein (i.e., Figuladra finlaysoni sp. nov., F. robertirwini sp. nov., F. bromileyorum sp. nov. and F. vidulus sp. nov.). The status of 11 previously described species has been assessed and revised diagnoses are provided for each of these. Species of the south-east Queensland clade revealed comparatively low levels of genetic and morphological differentiation and may represent examples of more recent, conceivably ongoing, speciation. Figuladra species have allopatric distributions with their ranges being separated by altitudinal or riverine barriers. Particularly the St Lawrence Gap dry corridor has been identified as a major biogeographic barrier separating two principal clades of Figuladra.

Detection of Babesia Spp., Theileria Spp., and Anaplasma Ovis in Ornithodoros Lahorensis from Southern Xinjiang, China.

Ticks are blood-sucking arthropods that have negative economic impacts and can spread a variety of diseases through their bites. There are few reports on soft ticks (Acari: Argasidae) and tick-borne pathogens in southern Xinjiang, China. This investigation supplements the available information for this region and is concerned with an argasid tick, apicomplexan parasites of the Babesia and Theileria genera and a bacterium of the Anaplasma genus. In this study, 330 soft ticks were collected from nine sampling sites in southern Xinjiang between 2020 and 2021. The ticks were identified according to their morphological characteristics and confirmed as Ornithodoros lahorensis using mitochondrial 16S rDNA sequences. Babesia and Theileria were identified at the species level based on two fragments of the 18S rRNA gene, and one set of primers targeting the 16S rRNA gene was used to identify the Anaplasma genus. Among the 330 samples, one Babesia species (Babesia sp.), two Theileria species (T. ovis and T. annulata), and one Anaplasma (A. ovis) species were detected. This study provides fundamental evidence for the occurrence of Babesia, Theileria and Anaplasma spp. in soft ticks. To the best of our knowledge, this is the first report of the detection of Babesia sp. and T. annulata in O. lahorensis. Therefore, the potential threat of soft ticks to livestock and humans should not be ignored.

Morphological and molecular confirmation of Ornithodoros hasei (Schulze, 1935) (Acari: Argasidae) in Colombia

A large number of tick species are proven vectors for the transmission of bacteria, protozoa, and viruses. Soft ticks (Acari: Argasidae) in South America have been found to be the most frequent carriers of borreliae of the relapsing fever group (RFG); however, there are several information gaps specially on the taxonomy and distribution of some tick species. Here, we used light microscopy, scanning electron microscopy, and PCR amplification of a fragment of the mitochondrial 16S rRNA gene to evaluate 174 larvae of Ornithodoros (Argasidae) collected from three bat species (Eptesicus orinocensis, Molossus rufus and Noctilio albiventris) in the Orinoquia Region of Colombia. The morphological and molecular results confirmed that all the analyzed larvae corresponded to Ornithodoros hasei. Comparisons of mitochondrial 16S rDNA sequences showed low genetic divergence (0% - 0.3%) between larvae of the Department of Arauca in the Orinoquia Region and higher genetic divergence (3.4 - 4.7%) in sequences from other American countries. Our work represents the most recent collection of this species in Colombia and provides a molecular evaluation for the first time. Moreover, a new association of O. hasei with bats such as E. orinocensis is documented. Considering the wide distribution of O. hasei in the American Continent, and its putative role as vector for Borrelia, integrative studies that involve morphological, morphometric, molecular data and experimental crosses are needed to determine if the higher genetic distances are associated with cryptic speciation, as detected in other tick complexes, or represent genetic divergences among geographically different populations of O. hasei.

Molecular characterization of Hyalomma dromedarii and evaluation of acaricidal potential of herbal methanolic extracts against H. dromedarii larvae in comparison to synthetic acaricides.

The present study had two aims: molecular characterization of Hyalomma dromedarii infesting one-humped camels of Haryana (North India), and assessment of the acaricidal potential of herbal methanolic extracts against H. dromedarii larvae in comparison to synthetic acaricides. Phylogenetics and population neutrality indices were assessed by targeting partial amplification of mitochondrial 16S rDNA sequences. Larval packet test (LPT) was performed to evaluate the acaricidal efficacy of herbal extracts (Ferula asafoetida and Trachyspermum ammi) and synthetic acaricides (deltamethrin and fipronil). Phylogenetic studies established the collected ticks to be H. dromedarii, exhibiting a homology of 99.8-100%. However, the present study isolates formed a different sub-clade compared to H. dromedarii sequences from Egypt, Senegal, Tunisia and Saudi Arabia. Nucleotide and haplotype diversity values were indicative of demographic expansion and low gene flow. Negative values of Tajima's D (-0.612) and Fu and Li's Fst (-0.479) highlighted deviations from neutrality and emphasized recent population expansion. The median lethal concentration (LC50) values recorded for T. ammi, F. asafoetida and their combination were 3.68, 2.87 and 2.59mg/mL, respectively, whereas the 90% lethal concentration (LC90) values were 4.09, 3.58 and 3.35mg/mL, respectively. It was also observed that the H. dromedarii population under study was completely susceptible to both the formulated synthetic acaricides. In conclusion, combination of methanolic extracts of F. asafoetida and T. ammi could provide a potential substitute to toxic synthetic chemical acaricides and might prove a valuable component of integrated tick management strategies.

Jianghuaimon dabiense gen. nov. et sp. nov (Crustacea: Decapoda: Potamidae), a new genus and new species of freshwater crab from eastern-central China.

A new genus and new species of freshwater crab, Jianghuaimon dabiense gen. et sp. nov., is described from Anhui and Hubei Provinces of China based on morphology and mitochondrial 16S rDNA sequences. Externally, the new genus resembles several other potamid genera from China. However, its combination of carapace, male pleon, third maxilliped, and uniquely structured male first gonopod distinguish it from the others. Phylogenetic analysis using the 16S gene supports the new genus new species and shows that it, together with morphologically similar Neilupotamon and Bottapotamon, form a distinct clade.

Revision of two species of Sinopotamon Bott, 1967 (Crustacea, Brachyura, Potamidae) endemic to China: a new combination and a new synonym.

The systematics of two problematic potamid species, Sinopotamonkoatenense (Rathbun, 1904) and Sinopotamonwuyiensis Li, Lin, Cheng & Tang, 1985, both originally described from the Wuyi Mountains are resolved in this study. Sinopotamonkoatenense is transferred to the genus Huananpotamon Dai & Ng, 1994, as the new combination Huananpotamonkoatenense comb. nov. The new combination differs from its congeners in the form of the carapace, male pleon, male first gonopod, and vulvae. Phylogenetic analyses based on mitochondrial 16S rDNA sequences support the identification of Huananpotamonkoatenense comb. nov. and a redescription is also provided. In addition, S.wuyiensis is confirmed as a junior synonym of Sinopotamonfukienense Dai & Chen, 1979 based on morphological similarities and phylogenetic lineages.

Two new species of freshwater crabs of the genera Huananpotamon Dai & Ng, 1994 and Minpotamon Dai & Türkay, 1997 (Decapoda: Brachyura: Potamidae) from eastern China

Abstract Two new Chinese species of potamid freshwater crabs, Huananpotamon shangyouensesp. nov. and Minpotamon auritumsp. nov., are described from Fujian and Jiangxi, eastern China, respectively. The two new species can be distinguished from their closest congeners by carapace features and structures of the male first gonopods. Phylogenetic analyses based on mitochondrial 16S rDNA sequences support the establishment of the two new species.

A new genus and new species of potamid crab from Yunnan, southern China (Decapoda: Brachyura: Potamidae: Potamiscinae)

Abstract A new genus and new species of freshwater crab, Barbamon zhouigen. nov., sp. nov., belonging to the subfamily Potamiscinae Bott, 1970 (Potamidae Ortmann, 1896) is described from Wenshan Zhuangzu and Miaozu Autonomous Prefecture, Yunnan Province, China. The new genus is established based on a unique combination of characters, including the distinctive shape of the male first gonopod, and the setose ventral surface of the third maxilliped, suborbital and pterygostomial regions, and ambulatory legs. Barbamongen. nov. is similar in external appearance to AbormonMitra, Pati & Ng, 2021. The new genus, however, is distinctive in the combination of characters related to the carapace, third maxilliped, and male first gonopod. Molecular phylogenetic data derived from mitochondrial 16S rDNA sequences provides genetic support for the new genus and species.

A new species of soft tick from dry tropical forests of Brazilian Caatinga

Ornithodoros tabajara n. sp. is described from laboratory-reared larvae and adult specimens collected in the Brazilian Caatinga. This new species shares the ecological niche with Ornithodoros rietcorreai and is likely associated with colonial rodents of genus Kerodon. However, O. tabajara n. sp. is morphologically easy to distinguish from O. rietcorreai and other Neotropical Ornithodoros by a unique combination of characters: larva with 17 pairs of dorsal setae (seven anterolateral, three central and seven posterolateral), sub-oval dorsal plate, hypostome blunt apically with dentition formula 2/2 along its extension, only one pair of posthypostomal setae, six pairs of sternal setae, posteromedian setae absent, and leave-shaped anal valves; alive adults with whitish islands of mammillae symmetrically distributed on dorsum (not visible in ethanol-preserved specimens), and median disk merging with posteromedian file. A phylogenetic analysis performed with mitochondrial 16S rDNA sequences points O. tabajara n. sp. as O. rietcorreai's sister taxon, which rises the hypothesis of sympatric speciation.

Morphological descriptions of the nymph and adults of Ornithodoros clarki, the larva and nymph of Ornithodoros rondoniensis, with notes on their phylogenetic relationships.

Based on tick specimens collected recently in Mexico, Nicaragua, Panama and Brazil, we provide morphological descriptions of the nymph and adults of Ornithodoros clarki Jones & Clifford, 1972 from the first three countries, and the larva and nymph of Ornithodoros rondoniensis (Labruna, Terassini, Camargo, Brandão, Ribeiro & Estrada-Peña, 2008) from Brazil. Also, an analysis of mitochondrial 16S rDNA sequences was performed to analyze the phylogenetic relationships of these tick species. Adults and nymphs of O. clarki and O. rondoniensis are unique among the Argasidae family by presenting exceptionally large spiracular plates with small goblets, and an integument with smooth polygonal mammillae. However, these two species are morphologically distinct based on specific patterns of coxal folds, idiosomal mammillae and pilosity, and female genital flap. In contrast, the larvae of O. clarki and O. rondoniensis are morphologically identical, except for a general larger size of the former species; this slight difference is corroborated by Principal Component Analysis (PCA) by using 40 morphometric variables. Phylogenetic analyses including 16S rDNA partial sequences of different Ornithodoros taxa from Central and South America indicate that O. rondoniensis from Brazil diverges from O. clarki from Mexico, Nicaragua and Panama. However, phylogenetic distance separating both alleged species is similar or slightly lower than the distances depicted for conspecific populations of a few other Ornithodoros species. Nonetheless, our primary criterion to maintain O. rondoniensis as a valid species is because its adult and nymphal stages do present distinct morphological traits that easily distinguish these postlarval stages from O. clarki.

Molecular Identification of Mid to Final Stage Slipper Lobster Phyllosoma Larvae of the Genus Chelarctus (Crustacea: Decapoda: Scyllaridae) Collected in the Pacific with Descriptions of Their Larval Morphology.

Morphological descriptions of phyllosoma larvae are essential for correct species identification and investigating the spatiotemporal distribution and recruitment process of spiny and slipper lobsters. Species identification of the phyllosoma larvae in the Scyllarinae subfamily is particularly difficult because of the morphological similarities among species and the scarcity of morphological information describing correct species identity. We extracted mid-to final-stage (V to VIII) phyllosoma larvae (n = 12) belonging to the subfamily Scyllarinae from several plankton samples collected in the Pacific and then performed molecular species identification using mitochondrial DNA COI and 16S rDNA sequence analyses. Three larvae collected around the Ryukyu Archipelago were identified as Chelarctus aureus (stage VI to VIII), and four collected around the Ryukyu Archipelago and Ogasawara Islands were identified as C. virgosus (V to VIII). One larva (V) collected in the central South Pacific was determined to be a subspecies of C. crosnieri. DNA barcodes could not be made for the remaining four larvae (V to VIII) collected around the Ryukyu Archipelago (designated by ?Chelarctus sp-1). Based on the morphological characteristics of the C. virgosus phyllosoma described in this study and the adult distributions reported to date, C. cultrifer phyllosomas previously reported in Japanese and Taiwanese waters are likely to be C. virgosus. This paper also presents a set of diagnostic morphological characteristics that can be used to discriminate among these four species of Chelarctus and from other genera in the subfamily Scyllarinae.

The Hillstream Decapod Crustaceans of Shenzhen, China, with Description of a New Species of Freshwater Crab (Crustacea: Brachyura: Potamidae) in the Genus Megapleonum Huang, Shih & Ahyong, 2018.

Freshwater decapod crustaceans are often ecologically important keystone species in their habitats. The freshwater hillstream decapods of Shenzhen City, Guangdong, China, were systematically surveyed for the first time from June to September 2019. We identified a total of 19 decapod species from 10 genera and six families. Of these, one Macrobrachium species and one potamid species could not be assigned to any known species. The latter clearly belongs to the monotypic genus Megapleonum Huang, Shih & Ahyong, 2018, and resembles the type species M. ehuangzhang in general external morphology. Striking differences in male gonopodal morphology along with genetic evidence based on mitochondrial 16S rDNA sequences strongly suggest that this species is distinct from the type species and it is herein described as Megapleonum shenzhen n. sp. Our survey data sheds light on the biodiversity of hillstream decapods in Shenzhen and highlights areas of conservation interest.

The second known stygomorphic freshwater crab from China, Phasmon typhlops gen. nov. et sp. nov. (Crustacea, Decapoda, Potamidae), diverged at the beginning of the Late Miocene.

A new genus and new species of blind freshwater cave crab are described from Chongzuo City, Guangxi Zhuang Autonomous Region, China based on morphology and mitochondrial 16S rDNA sequences. The new genus, Phasmongen. nov., is established for P. typhlopssp. nov., which is only the second blind cave crab known from China and East Asia. The combination of a very wide carapace, overall depigmentation, reduced orbits and vestigial unpigmented eyes of Phasmon immediately separates it from all known potamid genera. Molecular divergence estimates based on 16S rDNA suggest that the lineage to which the new genus belongs diverged from other potamids at the beginning of the Late Miocene (10.8 million years ago), much earlier than other Chinese cave crabs.

Phylogeny, species delimitation and population structure of the steppe-inhabiting land snail genusHelicopsisin Eastern Europe

AbstractWe here study the steppe-inhabiting land snail genus Helicopsis (Gastropoda: Geomitridae: Helicellinae) across Eastern Europe using mitochondrial 16S rDNA sequences and nuclear AFLP markers and compare the biogeographical patterns with those of other steppe-inhabiting organisms. The subdivision of Central and Eastern European Helicopsis reflects the geographical subdivision of the European steppe belt in Pontic, Pannonian and Northern steppes. The subdivision within Helicopsis is deeper, at the species level, than in most other steppe-inhabiting groups. Helicopsis populations from the Pontic steppes can be classified into two sister-species. Helicopsis lunulata includes mainly populations with depressed conical shells previously identified as H. striata, but also populations with disc-like shells previously identified as H. instabilis, and it is distributed mainly west of the Dnieper River. Most Helicopsis populations from east of the Dnieper, especially from Crimea, belong to the variable H. filimargo that includes H. gasprensis, H. retowskii, H. arenosa, H. luganica, H. martynovi and H. subfilimargo. The species inhabiting the Pannonian Basin and the Northern steppes form a well-supported monophylum, including H. hungarica in the Pannonian Basin, H. austriaca at the fringe of the Eastern Alps and H. striata mainly in the Northern steppes.

Descriptions of a new species of Minpotamon Dai & Türkay, 1997, and a monotypic new genus of aquatic freshwater crab (Brachyura, Potamidae) from eastern Guangdong, China

Abstract A new genus new species of freshwater crab and a new Minpotamon Dai & Türkay, 1997 species are described from eastern Guangdong, China, based on morphology and mitochondrial 16S rDNA sequences. The new genus, Teoswamon gen. nov., is established for T. scolasticum sp. nov., which resembles species from several other genera from Guangdong, but its unique combination of carapace, male gonopod and female vulvae characters set it apart from others. Minpotamon kityang sp. nov. is almost identical with Minpotamon nasicum (Dai, Chen, Song, Fan, Lin & Zeng, 1979) externally, but differs drastically in the male gonopod morphology. Molecular analysis supports the current taxonomic treatments. Teoswamon scolasticum sp. nov. forms its own lineage closely related to Huananpotamon Dai & Ng, 1994. Minpotamon kityang sp. nov. clusters with Minpotamon nasicum, but their genetic distance is of an interspecific level.

Two new species of freshwater crabs of the genera Eosamon Yeo & Ng, 2007 and Indochinamon Yeo & Ng, 2007 (Crustacea, Brachyura, Potamidae) from southern Yunnan, China.

Two new species of potamid crabs, Eosamon daiaesp. nov. and Indochinamon malipoensesp. nov. are described from the Sino-Burmese border, southwestern Yunnan and from the Sino-Vietnamese border, southeastern Yunnan, China. The two new species can be distinguished from their closest congeners by several characters, among which is the form of the first gonopod structures. Molecular analyses based on partial mitochondrial 16S rDNA sequences also support the systematic status of these new taxa.

A New Genus and Two New Species of Freshwater Crab (Crustacea: Brachyura: Potamidae) with Unusual Coiled Tip of Male Second Gonopods from Yunnan, Southwestern China.

Two new species of a new genus, Tortomon puer n. gen. n. sp. and T. gejiu n. gen. n. sp. are described from southern Yunnan, southwestern China, based on the morphology and mitochondrial 16S rDNA sequences. The new genus resembles Tenuipotamon Dai, 1990 and Parvuspotamon Dai & Bo, 1994, but can be separated by characters of the male thoracic sternum, male pleon, male first gonopod, and especially the coiled tip of the male second gonopod. The latter character easily separates Tortomon n. gen. from known potamid genera. Notes on the general biology of the two new species are also included.

A new long-legged terrestrial freshwater crab, Calcipotamon puglabrum gen. nov. et sp. nov. (Crustacea: Decapoda: Potamidae), from Hainan Island, China.

A new genus and new species of terrestrial freshwater crab, Calcipotamon puglabrum gen. nov. et sp. nov., is described from the limestone forests of Changjiang, Hainan Island, China, based on morphology and mitochondrial 16S rDNA sequences. The new genus is closest to Neotiwaripotamon Dai Naiyanetr, 1994, and Tiwaripotamon Bott, 1970, but differs in a combination of carapace, third maxilliped, ambulatory leg and male gonopod characters. Molecular analysis shows that the new genus is closely related with but not clustered within other Hainan potamid genera. Notes on the general biology of this new species are also provided.

Description of a new soft tick species (Acari: Argasidae: Ornithodoros) parasite of Octodon degus (Rodentia: Octodontidae) in northern Chile

A new argasid (Argasidae) tick is herein described based on morphology and molecular data obtained from larvae parasitizing Octodon degus and from ticks collected inside burrows in northern Chile. Unfed laboratory-reared larvae were mounted in slides for morphometrical and morphological analyses. Larvae of Ornithodoros octodontus n. sp. share morphological traits with Ornithodoros quilinensis and Ornithodoros xerophylus, two species associated with rodents in the Argentinean Chaco. However, a longer hypostome with two rows of 21 and 22 denticles each one, and conspicuous leaf-shaped anal plates separate O. octodontus. While nymphal stages of O. octodontus lack cheeks and possess a micromammillated dorsal integument, adults have cheeks and exhibit markedly irregular mammillae along their dorsal surface. Phylogenetic analyses of neotropical Argasidae based on mitochondrial 16S rDNA sequences point that O. octodontus forms a monophyletic group with O. xerophylus and an unidentified Ornithodoros sp. from Bolivia, all of them associated with burrow-dweller rodents. Ornithodoros aragaoi and Ornithodoros davisi, two rare species collected once only in the Peruvian Andean Plateau during 1955 are morphologically closely related with adults and nymphs of O. octodontus. Biological observations of O. octodontus revealed autogenic females. For the moment, subgeneric classification of this new species depends on further biological studies. The fauna of ticks occurring in Chile is now represented by 22 species, 11 belonging to the Argasidae family.

Genetic differentiation of the purpleback flying squid, Sthenoteuthis oualaniensis , in the South China Sea:population or species divergence

PDF HTML阅读 XML下载 导出引用 引用提醒 南海鸢乌贼的遗传差异: 种群分化还是种间分化 DOI: 作者: 作者单位: 中国水产科学研究院南海水产研究所, 农业农村部外海渔业开发重点实验室, 广东 广州 510300 作者简介: 李敏(1984-),男,博士,副研究员,从事海洋生物多样性和保护研究.E-mail:limin@scsfri.ac.cn 通讯作者: 中图分类号: S931 基金项目: 国家重点研发计划项目（2018YFC1406500）；农业农村部财政专项（NFZX2018）；广东省自然科学基金项目（2014A030310177）；国家重点基础研究发展计划项目（2014CB441500）. Genetic differentiation of the purpleback flying squid, Sthenoteuthis oualaniensis, in the South China Sea:population or species divergence Author: Affiliation: Key Laboratory of Open-Sea Fishery Development, Ministry of Agriculture and Rural Affairs;South China Sea Fisher-ies Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, China Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:利用线粒体ND2、COI和16S rDNA序列，对2012年9月至2015年9月采自南海的鸢乌贼（）样本进行了种群遗传结构的分析。系统发育关系显示鸢乌贼中型群和微型群各自形成了单系群分支，而分支内没有形成与地理群体或季节群体对应的支系。分子方差分析同样表明，地理群体或季节群体之间不存在明显的遗传分化，而中型群和微型群之间具有极显著的遗传分化（<0.0001）。遗传多样性分析显示，鸢乌贼中型群和微型群均呈现出较高的单倍型多样性（0.9465和0.8545）和较低的核苷酸多样性（0.0051和0.0021），中型群的遗传多样性指数要高于微型群。基于ND2、COI和16S rDNA序列计算的中型群和微型群之间的遗传距离分别达到了14.0%、9.6%和8.8%，远大于类群内的遗传分化（平均<1%）。研究结果表明，南海鸢乌贼存在分布高度重合且有显著遗传分化的两个种群，即中型群和微型群。中型群和微型群之间的遗传差异达到了种间分化的水平，提示体型较大、具有背部发光器的中型群鸢乌贼（典型鸢乌贼）与体型较小、背部发光器缺失的微型群鸢乌贼可能是两个相互独立的种类。 Abstract:In the present study, the population differentiation of the purpleback flying squid () in the South China Sea was examined based on mitochondrial ND2, COI, and 16S rDNA sequences, using samples collected between September 2012 and September 2015. Phylogenetic analysis revealed two significantly divergent monophyletic groups corresponding to the "medium form" and the "dwarf form, " but no geographical lineages corresponding to the sampling localities or seasonal groups were found. The Analysis of Molecular Variance also revealed significant genetic differentiation between the "medium form" and the "dwarf form" (<0.0001), while no genetic variance between either geographic populations or seasonal groups was found. The genetic diversity analysis showed that both the "medium form" and the "dwarf form" of in the South China Sea were characterized by high haplotype diversity (0.9465 and 0.8545) and low nucleotide diversity (0.0051 and 0.0021). The genetic distance between the ‘medium form’ and the "dwarf form" based on ND2, COI, and 16S sequences were 14.0%, 9.6%, and 8.8%, respectively. The genetic distances between the two forms were considerably larger than the genetic distances within each of the two forms (<1%). It was demonstrated that two divergent populations of were sympatrically distributed in the South China Sea, i.e. the "medium form" and the "dwarf form." The genetic differentiation between these two populations was similar to that among separate species within Ommastrephidae, which indicated that the two morphologically distinct forms of the purpleback flying squid, namely the "medium form" (middle sized, with a photophore) and the "dwarf form" (small sized, without a photophore), are two distinct species. 参考文献 相似文献 引证文献