Tomislav Karanovic

Cryptic Species or Inadequate Taxonomy? Implementation of 2D Geometric Morphometrics Based on Integumental Organs as Landmarks for Delimitation and Description of Copepod Taxa

Discovery of cryptic species using molecular tools has become common in many animal groups but it is rarely accompanied by morphological revision, creating ongoing problems in taxonomy and conservation. In copepods, cryptic species have been discovered in most groups where fast-evolving molecular markers were employed. In this study at Yeelirrie in Western Australia we investigate a subterranean species complex belonging to the harpacticoid genus Schizopera Sars, 1905, using both the barcoding mitochondrial COI gene and landmark-based two-dimensional geometric morphometrics. Integumental organs (sensilla and pores) are used as landmarks for the first time in any crustacean group. Complete congruence between DNA-based species delimitation and relative position of integumental organs in two independent morphological structures suggests the existence of three distinct evolutionary units. We describe two of them as new species, employing a condensed taxonomic format appropriate for cryptic species. We argue that many supposedly cryptic species might not be cryptic if researchers focus on analyzing morphological structures with multivariate tools that explicitly take into account geometry of the phenotype. A perceived supremacy of molecular methods in detecting cryptic species is in our view a consequence of disparity of investment and unexploited recent advancements in morphometrics among taxonomists. Our study shows that morphometric data alone could be used to find diagnostic morphological traits and gives hope to anyone studying small animals with a hard integument or shell, especially opening the door to assessing fossil diversity and rich museum collections. We expect that simultaneous use of molecular tools with geometry-oriented morphometrics may yield faster formal description of species. Decrypted species in this study are a good example for urgency of formal descriptions, as they display short-range endemism in small groundwater calcrete aquifers in a paleochannel, where their conservation may be threatened by proposed mining.

Explosive radiation of the genus Schizopera on a small subterranean island in Western Australia (Copepoda : Harpacticoida): unravelling the cases of cryptic speciation, size differentiation and multiple invasions

Abstract. n A previously unsurveyed calcrete aquifer in the Yilgarn region of Western Australia revealed an unprecedented diversity of copepods, representing 67% of that previously recorded in this whole region. Especially diverse was the genus Schizopera, with up to four morphospecies per bore and a significant size difference between them. Aims of this study were to: (1) survey the extent of this diversity using morphological and molecular tools; (2) derive a molecular phylogeny based on COI; and (3) investigate whether high diversity is a result of an explosive radiation, repeated colonisations, or both, size differentiation is a result of parallel evolution or different phylogeny, and whether Schizopera is a recent invasion in inland waters. More than 300 samples were analysed and the COI fragment successfully amplified by PCR from 43 specimens. Seven species and one subspecies are described as new, and three possible cryptic species were detected. Reconstructed phylogenies reveal that both explosive radiation and multiple colonisations are responsible for this richness, and that Schizopera is probably a recent invasion in these habitats. No evidence for parallel evolution was found, interspecific size differentiation being a result of different phylogeny. Sister species have parapatric distributions and show niche partitioning in the area of overlap.

Marine interstitial poecilostomatoida and cyclopoida (copepoda of Australia)

Copepods are top predators in the interstitial ecosystems and this book offers the first data about two large orders from the Australian marine interstitial. This exciting fauna abounds in new taxa, and this helped the author to recognize new zoogeographic regions in Australia.

A new species of Parastenocaris from Korea, with a redescription of the closely related P. biwae from Japan (Copepoda: Harpacticoida: Parastenocarididae)

Parastenocaris koreana sp. nov. is described based on examination of numerous adult specimens of both sexes from several localities in Korea. Scanning electron micrographs are used to examine intra- and interpopulation variability of micro-characters, in addition to light microscopy. The new species is most closely related to the Japanese P. biwae Miura, 1969, which we redescribe based on newly collected material from the Lake Biwa drainage area. The two species differ in size, relative length of the caudal rami, shape of the anal operculum, shape of the genital double somite, relative length of the inner distal process on the female fifth leg, as well as relative length of the apical setae on the second, third, and fourth legs exopods in both sexes. Detailed examinations of three disjunct populations of P. koreana reveal also some geographical variation, especially in the surface ornamentation of somites, which may indicate some population structuring or even cryptic speciation. Lack of intraspecific variability in the number and position of sensilla on somites, as well as their potential phylogenetic significance, is a novel discovery. Both species examined here belong to the brevipes group, which we redefine to include 20 species from India (including Sri Lanka), Australia, East Asia, Northern Europe, and North America. A key to species of this group is also provided. In order to test the monophyly of the redefined brevipes group with highly disjunct distribution, as well as relationship between different species, a cladistics analysis is performed based on 39 morphological characters and with help of three outgroup taxa. Six equally parsimonious cladograms are generated, all of which show that the ingroup is well defined by at least three synapomorphies. Reconstructed phylogeny questions the previously suggested hypothesis about the origin of this group in South East Asia, with one Australian species showing the most basal position. We speculate that the present distribution of this group may be a combination of ancient vicariance and subsequent dispersal, with a possible origin in the Gondwanaland, in the rift valley between Australia and India.

Redefinition of the parastenocaridid genus Proserpinicaris (Copepoda: Harpacticoida), with description of three new species from Korea

Proserpinicaris young sp. nov., Proserpinicaris wangpi sp. nov. and Proserpinicaris imjin sp. nov. are described from subterranean waters of South Korea. They are short-range endemics, allopatric in distribution and closely related to each other, and to two other Far Eastern congeners. Distinguishing features are limited to the general habitus shape, proportions of the caudal rami and degree of sexual dimorphism. The genus Proserpinicaris Jakobi, 1972, as redefined here, is Palaearctic in distribution, with the centre of diversity in southern Europe, and 20 valid members, all of which share a large hyaline spiniform structure on the male fourth leg basis as a synapomorphy. A key to species is provided. Genera Niponnicaris Jakobi, 1972 and Pannonicaris Jakobi, 1972 are established as its junior subjective synonyms, Lacustricaris Jakobi, 1972 is formally synonymized with Parastenocaris Kessler, 1913, and Parastenocaris lacustris Chappuis, 1958 is designated as incertae sedis in Fontinalicaridinae Schminke, 2010.

Two new subterranean ameirids (Crustacea : Copepoda : Harpacticoida) expose weaknesses in the conservation of short-range endemics threatened by mining developments in Western Australia

Abstract. The discovery of two new non-marine ameirids from the southern Yilgarn region significantly extends the geographic range for this group in Australia and exposes weaknesses in the conservation and environmental impact assessment (EIA) of subterranean species potentially threatened by mining developments. Megastygonitocrella embe, sp. nov. differs from seven previously described Australian congeners by the armature of the second leg endopod and absence of spinules on the somites. A key to world species of Megastygonitocrella is presented. Phylogenetic analysis based on 57 morphological characters and 30 species belonging to the Stygonitocrella s.l. group suggests that Antistygonitocrella pardalotos, gen. et sp. nov. has no close relatives anywhere in the world. Superficial similarities between the two new species are either plesiomorphies or homoplasies. The habitats of these new short-range endemic species are fractured-rock aquifers developed in Archaean greenstone, where the groundwater is characterised by acid conditions, high salinity and low dissolved oxygen. The population of A. pardalotos is threatened by a mining development. Despite the advanced level of environmental protection policy in Western Australia, our taxonomic study highlights limitations in EIA practices and discusses potential improvements which have global relevance in regions where short-range endemics coincide with extraction of mineral resources.

New insights into polyphyly of the harpacticoid genus Delavalia (Crustacea, Copepoda) through morphological and molecular study of an unprecedented diversity of sympatric species in a small South Korean bay

Polyphyly of the genus Delavalia Brady, 1869 has been postulated previously based on intuitive methods, but no phylogenetic study was ever conducted. A chance discovery of seven sympatric species of this genus in the highly industrialized Gwangyang Bay in South Korea, in addition to one species each from the closely related genera Stenhelia Boeck, 1865 and Onychostenhelia Itô, 1979, prompted a renewed interest in the phylogenetic relationships within the subfamily Stenheliinae Brady, 1880. Additional surveys along the Korean coast failed to produce Delavalia species, but comparative material was sourced from Posyet Bay in the Russian Far East. Aims of this study were to reconstruct phylogenetic relationships of the newly collected stenheliins using molecular methods, test the hypothesized polyphyly of Delavalia, formally describe any resulting monophyletic units, perform a comparative study of traditional morphological and novel micro-morphological characters, and describe all new Delavalia species. A fragment of the mtCOI gene was successfully PCR-amplified from 23 stenheliin specimens and an additional 300 specimens were studied for morphological characters. All phylogenetic analyses supported the presence of at least eight genetically divergent lineages, most with very high bootstrap values, and the polyphyletic nature of Delavalia is demonstrated. Three new genera, each supported by molecular data and a number of morphological synapomorphies, were erected to accommodate the newly discovered species and some previously described members of Delavalia: Wellstenhelia gen. nov., Itostenhelia gen. nov., and Willenstenhelia gen. nov. The Chinese Wellstenhelia qingdaoensis (Ma & Li, 2011) comb. nov. is recorded for the first time in Korea, and six new species are described from Gwangyang Bay: Wellstenhelia calliope sp. nov., Wellstenhelia clio sp. nov., Wellstenhelia erato sp. nov., Wellstenhelia euterpe sp. nov., Itostenhelia polyhymnia sp. nov., and Willenstenhelia thalia sp. nov. Additonally, Itostenhelia golikovi (Chisleno, 1978) comb. nov. is redescribed from newly collected material from the type locality in Russia and its male described for the first time, while Wellstenhelia melpomene sp. nov., Willenstenhelia urania sp. nov., and Willenstenhelia terpsichore sp. nov. are established as new names for previously reported populations of two presumably widely distributed Delavalia species.

Endemism of subterranean Diacyclops in Korea and Japan, with descriptions of seven new species of the languidoides-group and redescriptions of D. brevifurcus Ishida, 2006 and D. suoensis Ito, 1954 (Crustacea, Copepoda, Cyclopoida).

Abstract Copepods have been poorly studied in subterranean habitats in Korea. Previous records have indicated mostly the presence of species already described from Japan, with very few endemic elements. This commonality has usually been explained by repeated dispersal across the land bridges that connected the two countries several times during the Pleistocene glacial cycles. However, the Korean Peninsula is known for pockets of Cambrian and Ordovician carbonate rocks, with more than 1,000 caves already having been explored. The relative isolation of these carbonate pockets makes for an enormous speciation potential, and the development of a high level of short-range endemism of subterranean copepods should be expected. Representatives of the genus Diacyclops Kiefer, 1927 are here investigated from a range of subterranean habitats in South Korea, with comparative material sampled from central Honshu in Japan. Morphological analyses of microcharacters, many of which are used in cyclopoid taxonomy for the first time herein, reveal high diversity in both countries. No subterranean species is found in common, although the existence of four sibling species pairs in Korea and Japan may be indicative of relatively recent speciation. We describe seven new stygobiotic species, including three from Korea (Diacyclops hanguk sp. n., Diacyclops leeae sp. n., and Diacyclops parasuoensis sp. n.) and four from Japan (Diacyclops hisuta sp. n., Diacyclops ishidai sp. n., Diacyclops parahanguk sp. n., and Diacyclops pseudosuoensis sp. n.). Diacyclops hanguk, Diacyclops parasuoensis, Diacyclops ishidai, and Diacyclops parahanguk are described from newly collected material, while the other three new species are proposed for specimens previously identified as other, widely distributed species. Diacyclops brevifurcus Ishida, 2006 is redescribed from the holotype female, and Diacyclops suoensis Ito, 1954 is redescribed from material newly collected near the ancient Lake Biwa in Japan. This research provides evidence for the importance of subterranean habitats as reservoirs of biodiversity, and also demonstrates the inadequacy of current morphological methods of identifying closely related species of copepods. The disproportionately high diversity discovered around Lake Biwa provides further evidence in support of the hypothesis about the role of ancient lakes as biodiversity pumps for subterranean habitats. A key to the East Asian species of the languidoides-group is provided.

Morphological and molecular affinities of two East Asian species of Stenhelia (Crustacea, Copepoda, Harpacticoida)

Abstract Definition of monophyletic supraspecific units in the harpacticoid subfamily Stenheliinae Brady, 1880 has been considered problematic and hindered by the lack of molecular or morphology based phylogenies, as well as by incomplete original descriptions of many species. Presence of a modified seta on the fifth leg endopod has been suggested recently as a synapomorphy of eight species comprising the redefined genus Stenhelia Boeck, 1865, although its presence was not known in S. pubescens Chislenko, 1978. We redescribe this species in detail here, based on our freshly collected topotypes from the Russian Far East. The other species redescribed in this paper was collected from the southern coast of South Korea and identified as the Chinese S. taiae Mu & Huys, 2002, which represents its second record ever and the first one in Korea. A fragment of the mtCOI gene was successfully PCR-amplified from two specimens of each species, which represents the first molecular data for this genus, and from additional 19 specimens belonging to six different species of other stenheliins from Korea and Russia. Reconstructed phylogenies confirm previously postulated monophyly of Stenhelia and polyphyly of the closely related genus Delavalia Brady, 1869. Average pairwise maximum likelihood distances between S. pubescens and S. taiae are only slightly above 10%, suggesting a very close relationship despite numerous newly discovered micro-morphological differences and despite macro-morphological similarities being probable plesiomorphies.

A new species of Enhydrosoma (Copepoda: Harpacticoida: Cletodidae) from Korea, with redescription of E. intermedia and establishment of a new genus

Abstract Two species of Enhydrosoma Boeck, 1873, found in muddy sediments in the sublittoral zone of Gwangyang Bay, represent the first record of this genus in Korea. Enhydrosoma coreana, new species, shares a number of rare morphological features with the type species, E. curticauda Boeck, 1872, such as a bifid rostrum with centrally inserted sensilla, endopodal lobe of P5 with a peduncle, and a characteristic shape of the female genital field. They differ in the armature formula of the mandible, P1 endopod, and P5 exopod, size of the P5 peduncle, and minor details in the ornamentation of several somites. Enhydrosoma intermedia Chislenko, 1978 is redescribed from its holotype, freshly collected Korean material, and freshly collected material from and near its type locality in the Russian Far East. Its male is described for the first time. Minor morphological differences are observed between these two disjunct populations, such as longer caudal rami and sparse hair-like spinules on somites in Korean specimens. However, molecular data from the mtCOI gene suggest them to be conspecific. Detailed morphological comparisons between E. coreana and E. intermedia reveal a number of important differences, and molecular phylogenies suggest only a remote relationship. Their average pairwise maximum likelihood distances are very similar to those between other well-established genera of harpacticoid copepods. Geehyndrosoma, new genus, is erected to accommodate E. intermedia, together with E. brevipodum Gómez, 2004, from the Pacific coast of Mexico.