The morphology and taxonomy of the Antarctic species of Tritonia Cuvier, 1797 (Nudibranchia: Dendronotoidea)

The external morphology and anatomy of the Antarctic nudibranchs Tritonia vorax Odhner, 1926, and Tritonia antarctica Pfeffer in Martens & Pfeffer, 1886, is redescribed in detail and compared with other nominal tritoniids from the Antarctic and Subantarctic waters. Tritonia appendiculata Eliot, 1905, T. challengeriana Eliot, 1907a, non Bergh, 1884, T. chalkngeriana Odhner 1926, non Bergh, 1884, and Marionia cmullata Vicente & Arnaud 1974, non (Couthouy, in Gould 1852), are shown to be synonymous with T. antarctica. Only Tritonia antarctica is a true High Antarctic species, with a distribution around the continental shelf, Antarctic Peninsula and South Georgia. T. vorax is confined to South Georgia and Subantarctic waters.     

Phylogeny of Australian species of flatheads (Teleostei, Platycephalidae) as determined by allozyme electrophoresis

Phylogenetic relationships of 24 taxa of Platycephalid fish were examined for up to 40 loci using starch and polyacrylarnide gel electrophoresis. Over 400 different enzyme mobilities were scored. The extent of homoplasy was estimated to be between 5 and 12%. Polymorphism at the 1% level was observed at 26 of the 40 loci. The importance of shared polymorphic alleles in cladistic analysis was endorsed by the different results obtained from multistate and binary coding of alleles. Many loci were shown to contain phylogenetically informative ancestral alleles which appear irregularly in extant species. The polymorphism parsimony method provided the most informative results. Genetic similarities between endemic Australian species from each family stem provide the basis for a major revision of subfamilies and genera within the family.     

Biochemical differentiation of two groups within the species-complex Henricia Gray, 1840 (Echinodermata, Asteroidea) using starch-gel electrophoresis

Eighteen specimens from the Henricia pertusa group and 12 from the H. perforata group were examined for biochemical differences at the glucose-1-phosphate isomerase (GPI^* locus). Six alleles were found. Neither group showed deviations from Hardy Weinberg equilibrium (HW) (H. pertusa group: P1, H. perforata group: P=0.07, confidence interval=0.066–0.076). Significant differences in allele frequencies between the two groups (P0), supported previous assertions of reproductive isolation between the two groups based on morphological differences. However, near significance in HW disequilibrium in the H. perforata group indicates possible substructure in this group.     

Detection by allozyme electrophoresis of cryptic species of Hypodontus macropi (Nematoda: Strongyloidea) from macropodid marsupials.

Allozyme electrophoresis of 98 Hypodontus macropi from eight different species of hosts using 24 enzymes revealed a complex of at least six sibling species, with 15-50% fixed genetic differences between taxa. Except for the taxon parasitizing Macropus rufus/M. robustus, pairs of parasite taxa were, in each case, sympatric at each locality examined, thus supporting the conclusion that they represent valid species. The existence of a series of host-specific nematode taxa explains many of the inconsistencies noted previously in the host distribution of H. macropi. Comparison of parasite allozyme phenograms with host phylogeny suggests that four of the speciation events could be attributable to cospeciation and two to host switching. A clear case of host switching between M. rufus/M. robustus and M. fuliginosus was found.     

Isozyme and allozyme markers distinguishing two morphologically similar, medically important Mastomys species (Rodentia: Muridae)

Background  

Two common southern African mice species, Mastomys coucha and M. natalensis, are widely distributed throughout the subregion and overlap in many areas. They also share a high degree of morphological similarity, making them impossible to distinguish in the field at present. These multimammate mice are documented carriers of serious disease vectors causing Lassa fever, plague and encephalomyocarditis, which coupled to their cohabitation with humans in many areas, could pose a significant health risk. A preliminary study reported the presence of isozyme markers at three loci (GPI-2, PT-2, -3) in one population each of M. coucha and M. natalensis. Two additional populations (from the Vaal Dam and Richards Bay) were sampled to determine the reliability of these markers, and to seek additional genetic markers.     

A tropical Atlantic species of Melibe Rang, 1829 (Mollusca,Nudibranchia, Tethyiidae)

A new species of Melibe is described based on two specimens collected in Florida. This new species is well differentiated morphologically and genetically from other species of Melibe studied to date. The four residue deletions in the cytochrome c oxidase subunit 1 protein found in all previously sequenced tropical species of Melibe sequenced (and Melibe rosea) are also present in this new species. These deletions do not appear to affect important structural components of this protein but might have fitness implications. This paper provides the first confirmed record of Melibe in the tropical western Atlantic Ocean.     

Phylogenetic relationships of two Salamandrella species as revealed by mitochondrial DNA and allozyme variation (Amphibia: Caudata: Hynobiidae)

We conducted molecular phylogenetic analyses to confirm taxonomic relationships and to delimit distributional ranges of Siberian salamanders, Salamandrella keyserlingii and Salamandrella schrenckii, and to elucidate the origin of the isolated population of this species complex on Hokkaido, Japan. Phylogenetic trees constructed by MP, NJ, ML, and Bayesian methods, using complete sequences of mitochondrial cytochrome b genes, all indicated monophyly of Salamandrella and of each of the two species. Identical relationships were found on UPGMA, NJ, and CONTML trees derived from electrophoretic analysis of variation in 18 inferred allozyme loci. Populations from Hokkaido and northeastern China proved to be S. keyserlingii, while populations from Khabarovsk and Lazovsky are S. schrenckii. Genetic differentiations of S. keyserlingii within Sakhalin, and between Sakhalin and Hokkaido, are substantial. The Hokkaido population is hypothesized to have been isolated on the island since early Pleistocene, much earlier than isolation of sympatric anuran populations from their Sakhalin relatives. In contrast, the continental populations of S. keyserlingii are only slightly differentiated from some Sakhalin populations, and are thought to have expanded their ranges in the late Pleistocene.     

Characterization of feeding habits,prey diversity and diet overlap of two sympatric species: Bronze catfish,Netuma bilineata (Valenciennes, 1840) and blacktip sea catfish,Plicofollis dussumieri (Valenciennes, 1840) in the northern Arabian Sea

This study describes the diet composition, diet overlap and prey diversity in two economically and ecologically important marine catfish species: the bronze catfish (Netuma bilineata) and the blacktip sea catfish (Plicofollis dussumieri) collected between January and December 2015 from the northern Arabian Sea coast of Pakistan. Stomach data of 342 bronze catfish and 283 blacktip sea catfish were examined. Diet composition and feeding strategy of each species by identification of stomach contents were weighed and enumerated. Both species primarily consumed teleosts, Brachyura and small amounts of a wide variety of prey items; however, specialization was a more common trait for the bronze catfish than for the black tip sea catfish. The Morisita‐Horn index showed considerable diet overlap in percentage of mean weights (0.847) than in numbers (0.612) between co‐prey pairs of both species. The highest Bray‐Curtis similarity between the southwest monsoon (SWM) and south inter monsoon (SIM) was observed in bronze catfish and lowest between autumn inter monsoon (AIM) seasons in both species. While Bray‐Curtis dissimilarity was observed, both species share diet niches and diet overlap. The present study evaluation of the feeding strategy and potential competition between two sympatric species of marine catfishes can provide the framework for their conservation and management in the region.     

High levels of allozyme variation within populations and low allozyme divergence within and among species of Hemerocallis (Liliaceae)

Thirty populations from five species of Hemerocallis in Korea were analyzed by starch gel electrophoresis to measure genetic diversity and to determine genetic population structure and the amount of genetic divergence within and between species at 12 isozyme loci. In addition, Moran's I spatial autocorrelation statistics were used to examine the spatial distribution of allozyme polymorphisms in populations of H. thunbergii and H. hakuunensis. Populations of five Korean species maintain high levels of genetic variation and little differentiation among populations and species. Mean expected heterozygosities range from 0.165 in H. hongdoensis, an island endemic, to 0.265 in H. taeanensis, and a total of 81 alleles across the 12 loci were detected in the five species. G(ST) values for each of the five species were low, ranging from 0.051 in H. taeanensis to 0.078 in H. hakuunensis. Mean intraspecific Nei's genetic identities (I) between populations of the five species were all above 0.97. However, a considerable level of heterozygote deficiencies within populations was detected, ranging from 0.242 to 0.411 measured as F(IS) statistics. This deficiencies may be due to inbreeding, limited pollen and seed dispersal, or from the pooling of subpopulations that differ in allele frequencies. A small spatial scale population substructuring (<12 m) was found in H. thunbergii and H. hakuunensis. A group of populations from each of the five previously designated Hemerocallis species (based on their morphology, ecology, and phenology) agrees with our allozyme data, though pairwise comparisons among species had high I values (from 0.862, H. middendorffii vs. H. hongdoensis, to 0.969, H. thunbergii vs. H. taeanensis). This is attributed to the presence of the same high-frequency alleles in different species at seven loci. In addition, no "diagnostic allele" that appears in all populations of one species, but is absent in other species, was detected at the 12 isozyme loci. These all suggest that species of Hemerocallis in Korea may have recently derived from an ancestor or progenitor harboring high levels of genetic diversity.     

The phylogeny of Halgerda (Opisthobranchia, Nudibranchia) with the description of a new species from Okinawa

This paper proposes a refined hypothesis of evolution for the tropical Indo-Pacific nudibranch genus Halgerda . Numerous specimens from 31 species were examined anatomically and literature from four additional species was reviewed, bringing to 33 the ingroup taxa. Fifty-three characters were considered from these examinations. The outgroup Asteronotus was used to polarize the characters. The phylogeny obtained from the analysis of the characters supports the hypothesis that Halgerda is a monophyletic group. A species previously placed with the genus Sclerodoris is examined and determined to be a member of the genus Halgerda . Phylogenetic analysis places this species, H. paliensis , as a basal member of the genus . Halgerda paliensis appears to be restricted to the Hawaiian Islands. Specimens previously identified as Sclerodoris paliensis from the Marshall Islands actually represent H. dalanghita Fahey & Gosliner, 1999. A new species, Halgerda onna , is described and presented as the sister taxon to a basal member of the genus. A range and depth extension of a previously described species, H. malesso , is presented. The present phylogeny is then compared to previous studies, in particular those of Fahey & Gosliner (1999a,b) .     

A new species of Armodoris (Mollusca, Gastropoda, Nudibranchia, Akiodorididae) from McMurdo Sound, Antarctica

Recently collected specimens of Armodoris from McMurdo Sound, Antarctica, were morphologically examined and sequenced. Comparison between this new material and literature sources revealed that it belongs to an undescribed species, Armodoris anudeorum. Although this new species is externally very similar to Armodoris antarctica (the only previously known species of Armodoris), these two species differ in several details of their external morphology, and particularly in their reproductive anatomy and radular morphology. This is the second known species of Armodoris; thus, this paper doubles the known diversity of this exclusively Antarctic group.     

Review of the genus Ctenopseustis Meyrick (Lepidoptera: Tortricidae), with reinstatement of two species

Abstract

The genus Ctenopseustis Meyrick (Tortricinae: Archipini) is reviewed. The species C. fraterna Philpot, 1930 and C. servana Walker, 1863 are reinstated, and the concept of C. obliquana (Walker, 1863) is redefined. Synonymies are given for each species, and characteristics are described and illustrated.     

Eumetazoan parasites of two marine fish species from Baja California,Mexico: Sebastes miniatus (Jordan & Gilbert, 1880) and Caulolatilus princeps (Jenyns, 1840)

It is hypothesized that two fish species sharing a same demersal habitat might show a similar community of parasites. The aim of this study was to compare the parasite community component of of two marine fishes on the northwest coast of México of economical interest, the vermilion rockfish Sebastes miniatus and the ocean whitefish Caulolatilus princeps. From February to December 2005, 210 specimens of S. miniatus (85–550 mm total length TL) and 91 C. princeps (85–550 mm TL) were obtained from the San Quintín sportfishing catch, at Pacific Baja California. Skin, eyes, fins and gill cavity were examined in situ, and their internal organs removed for later analysis, including a portion of flesh. In S. miniatus, 12 parasite taxa were identified as belonging to Monogenea, Digenea, Cestoda, Nematoda, Acanthocephala and Copepoda; the stomach, pyloric caeca, and intestine (digestive tract) were the most parasitized organs with seven of the 12 species. In S. miniatus, the most abundant parasite was Parabothriocephalus sagitticeps (80.8 individuals/host ± 33.4 SE: standard error), highest prevalence was Microcotyle sebastis (92.6%), and the highest average intensity of infection was the cestode P. sagitticeps (190.4 ± 48.1 SE). The C. princeps showed six species belonging to Monogenea, Digenea, Nematoda and Copepoda; the digestive tract presented the greatest infestation, with four of the six species recorded. The most abundant nematode was Hysterothylacium aduncum (16.5 ± 3.5 individuals/host), the main prevalent species was Anisakis sp., and the highest value of infection intensity was by Hatschekia sp. The nematodes Anisakis sp. and H. aduncum were shared between the two host fishes, and are a zoonotic risk to humans if the fishes are not cooked properly.     

Discrimination of Cricotopus species (Diptera: Chironomidae) by DNA barcoding

Chironomids (Diptera) typically comprise the most abundant group of macroinvertebrates collected in water quality surveys. Species in the genus Cricotopus display a wide range of tolerance for manmade pollutants, making them excellent bioindicators. Unfortunately, the usefulness of Cricotopus is overshadowed by the difficulty of accurately identifying larvae using current morphological keys. Molecular approaches are now being used for identification and taxonomic resolution in many animal taxa. In this study, a sequence-based approach for the mitochondrial gene, cytochrome oxidase I (COI), was developed to facilitate identification of Cricotopus species collected from Baltimore area streams. Using unique COI sequence variations, we developed profiles for seven described Cricotopus sp., four described Orthocladius sp., one described Paratrichocladius sp. and one putative species of Cricotopus. In addition to providing an accurate method for identification of Cricotopus, this method will make a useful contribution to the development of keys for Nearctic Cricotopus.     

Purification and properties of two endo-1,4-beta-xylanases from Irpex lacteus (Polyporus tulipiferae)

Two different endo-1,4-beta-xylanases [1,4-beta-D-xylan xylanohydrolases, EC 3.2.1.8], named Xylanases I and III, were purified to homogeneity by gel filtration and ion exchange column chromatography from Driselase, a commercial enzyme preparation from Irpex lacteus (Polyporus tulipiferae). The purified enzymes were found to be homogeneous on polyacrylamide disc electrophoresis and their specific activities toward xylan were increased approximately 28.7 and 19.8 times, respectively. The activities of each enzyme were considerably inhibited by Hg2+, Ag+, and Mn2+. Their molecular weights were estimated to be approximately 38,000 and 62,000 by gel filtration and sodium dodecyl sulfate (SDS)-polyacrylamide electrophoresis, respectively. Their carbohydrate contents were 2.5% and 8.0% as glucose, and their amino acid composition patterns resembled each other, showing high contents of acidic amino acids, serine, threonine, alanine, and glycine. Both enzymes were most active at pH 6.0 but Xylanase I was more stable as to pH. Their optimum temperatures were 60 degrees C and 70 degrees C, respectively. Xylanase I split up to 34.5% of larchwood xylan whereas Xylanase III split only 18.9% of it. The products with the former were mainly xylose (X1), xylobiose (X2), and xylotriose (X3), whereas X2 and X3 were the main products with the latter. Both enzymes did not hydrolyze X2. Xylanase I produced almost equal quantities of X1 and X2 from X3, while Xylanase III did not attack this substrate. Both enzymes showed no activity toward glycans, other than xylan, such as starch, pachyman and Avicel (microcrystalline cellulose), except the almost one twentieth activity of Xylanase III toward sodium carboxymethyl cellulose (CMC).     

A new species of Trapania (Nudibranchia: Goniodorididae) from the Pacific coast of Central America

A new marine gastropod species of the genus Trapania Pruvot-Fol, 1931, is described from Cabo Blanco, Puntarenas, Costa Rica and from Islas Secas, Panamá. Trapania inbiotica sp. nov. has a white body with red patches, white rhinophores with some little red patches, yellow appendages with partially red bases. The radula is composed of 28 rows of teeth. Each tooth has a large conical cusp with 21-24 denticles. Two or three of those denticles on the inner side of the cusp are smaller than the others. There are also 1-3 small denticles on the outside of the cusp. The jaw elements are very irregular.