Ivo Karaman

Chemosystematics in the Opiliones (Arachnida): a comment on the evolutionary history of alkylphenols and benzoquinones in the scent gland secretions of Laniatores.

Large prosomal scent glands constitute a major synapomorphic character of the arachnid order Opiliones. These glands produce a variety of chemicals very specific to opilionid taxa of different taxonomic levels, and thus represent a model system to investigate the evolutionary traits in exocrine secretion chemistry across a phylogenetically old group of animals. The chemically best‐studied opilionid group is certainly Laniatores, and currently available chemical data allow first hypotheses linking the phylogeny of this group to the evolution of major chemical classes of secretion chemistry. Such hypotheses are essential to decide upon a best‐fitting explanation of the distribution of scent‐gland secretion compounds across extant laniatorean taxa, and hence represent a key toward a well‐founded opilionid chemosystematics.

On the enigmatic scent glands of dyspnoan harvestmen (Arachnida, Opiliones): first evidence for the production of volatile secretions

While considerable knowledge on the chemistry of the scent gland secretions from the opilionid suborders Laniatores and Cyphophthalmi has been compiled, it is the Palpatores (Eupnoi and Dyspnoi) where chemical data are scarce. In particular, the Dyspnoi have remained nearly unstudied, mainly due to their reported general reluctance to release secretions as well as to the phenomenon of production of insoluble—and inaccessible—solid secretion. We here show that at least certain nemastomatid Dyspnoi, namely all three species of genus Carinostoma, indeed produce a volatile secretion, comprising octan-3-one, 6-methyl-5-hepten-2-one and acetophenone in species-specific combinations. In all Carinostoma spp., these volatiles are embedded in a semi-volatile, naphthoquinone matrix (mainly 1,4-naphthoquinone and 6-methyl-1,4-naphthoquinone). In detail, acetophenone and traces of naphthoquinones characterize the secretions of Carinostoma carinatum. A mixture of octan-3-one, 6-methyl-5-hepten-2-one and large amounts of naphthoquinones were found in C. elegans, and 6-methyl-5-hepten-2-one together with small amounts of naphthoquinones in the secretions of C. ornatum. So far, exclusively naphthoquinones had been reported from a single dyspnoan hitherto studied, Paranemastoma quadripunctatum.

Nitrogen-Containing Compounds in the Scent Gland Secretions of European Cladonychiid Harvestmen (Opiliones, Laniatores, Travunioidea)

The exocrine secretions from prominently developed prosomal scent glands in four species of the European laniatorean harvestman genus Holoscotolemon (Laniatores, Travunioidea, Cladonychiidae) were analyzed by gas chromatography – mass spectrometry. Two major alkaloidal compounds were detected: Nicotine accounted for more than 97% of the secretion in Holoscotolemon jaqueti and H. oreophilum, whereas the chemically related nicotinoid alkaloid anabaseine was the major compound in H. lessiniense. In addition, a series of minor nitrogen-containing components was found, namely 3-(1-methyl-2-piperidinyl)-pyridine and anabasine, in H. jaqueti and H. oreophilum, and anabasine together with 2,3′-bipyridyl in H. lessiniense. By contrast, extracts of adult H. unicolor did not show any components. In one juvenile specimen of H. unicolor, however, low amounts of alkyl pyrazines (dimethyl-isobutyl- and dimethyl-isopentylpyrazines) were detected. Nitrogen-containing components previously were found in Sclerobunus robustus (an American travunioid harvestman), so scent gland-derived alkaloids may be widespread or even common in the Travunioidea. Alkaloids have not been reported for other opilionid scent gland secretions outside the Travunioidea, and we hypothesize that they may be the phylogenetically ancestral allomones in the Laniatores, having been reduced and replaced by a phenol- and benzoquinone-rich chemistry in the more derived grassatorean taxa.

High Conservatism in the Composition of Scent Gland Secretions in Cyphophthalmid Harvestmen: Evidence from Pettalidae

The scent gland secretion of Austropurcellia forsteri was analyzed by gas chromatography–mass spectrometry, providing the first description of the secretion chemistry in the cyphophthalmid family Pettalidae. The secretion contained a total of 21 compounds: About 60% of the whole secretion consisted of a series of saturated, mono-unsaturated and doubly unsaturated methylketones, from C11 to C15, with a cluster of saturated and mono-unsaturated C13-methylketones dominating. A second fraction included several naphthoquinones such as 1,4-naphthoquinone (ca. 20% of secretion), 6-methyl-1,4-naphthoquinone (ca. 17%), and minor amounts of chloronaphthoquinones (ca. 2%). When compared with scent gland compositions of other representatives of cyphophthalmids (e.g. from families Sironidae and Stylocellidae), a highly conservative chemistry of cyphophthalmid secretions is apparent, based on a restricted number of methylketones and naphthoquinones.

Macedonethes stankoi n. sp., a rhithral oniscidean isopod (Isopoda: Oniscidea: Trichoniscidae) from Macedonia

Abstract Macedonethes stankoi n. sp. is described, a truly aquatic species with special morphological adaptations to life in running water. Diagnosis of Macedonethes stankoi n. sp. (Fig. 1): Species with the characters diagnostic for Macedonethes Buturovic, 1955 (see also Tabacaru 1993). Blind. Body large (up to 15.7 mm long), rather convex. Defined mostly by characters interpreted as adaptations to life in rhithral habitats: cephalon hypognathous, antennular article 3 and aesthetascs reduced to varying degree (from slightly developed with two aesthetascs to almost totally reduced); pereopods 1–4 subchelate, i.e. with elongate carpus opposed to propodus and dactylus (enabling the animal to attach tightly to the substrate); sternum of pereonite 5 with unique clasping structures (presumably facilitating copulation); exopod of male pleopod 1 remarkably dilated mediodistally; endopod of male pleopod 2 with arched apical article; exopods of pleopods 2–5 with long plumose setae on posterior margins; epimera of pleonites 3–5 well developed. Types and locality: Holotype male (Macedonian Museum of Natural History, Skopje; Inv. No. 2783); Macedonia, Jakupica Mt., slopes of Solunska glava peak, from a spring in the cave at the source of the Babuna River, 1500 m asl (UTM-EM31), 18.08.2000, leg. G. Poliic. Paratypes: 4 males and 2 females as holotype (Inv. No. 2784); 2 males and 1 female as holotype, except in authors collection; 1 male and 1 female as holotype, except in Museo Zoologico “La Specola”, University of Florence, Italy. Spelaeonethes castellonensis Cruz & Dalens, 1989 clearly differs from the characteristics of Spelaeonethes species, particularly in structures of the male merus 7 and the endopods of male pleopods 2. Published descriptions and illustrations demonstrate obvious close relations with the type species of Macedonethes , M. skopjensis Buturovic, 1955, especially regarding all characters considered diagnostic for that genus. Therefore, the new combination Macedonethes castellonensis (Cruz & Dalens) is proposed. A detailed description (including color plates), further discussion of adaptations, and data on other aquatic oniscids are presented in an Electronic Supplement.

In vitro antibiofilm activity of the freshwater bryozoan Hyalinella punctata: a case study of Pseudomonas aeruginosa PAO1

Abstract The antibiofilm and possible antiquorum sensing effects against the strain Pseudomonas aeruginosa PAO1 of five crude extracts of the freshwater bryozoan Hyalinella punctata (Hancock, 1850) were evaluated in vitro for the first time. H. punctata ethyl acetate extract (HpEtAc) exhibited the highest antibiofilm activity reducing the biofilm formation of P. aeruginosa PAO1 in the range of 80.63–88.13%. While all tested extracts reduced the twitching motility of the aforementioned bacterial strain, HpEtAc showed to be the most effective. Finally, at a concentration of 0.5 MIC, the same extract mostly inhibited the production of pyocyanin by P. aeruginosa PAO1 (71.53%). In comparison both with the positive controls used (streptomycin and ampicillin, 67.13 and 69.77%, respectively), HpEtAc was found to inhibit pyocyanin in a higher extent. An extensive chemical characterisation of this particular extract may result in isolation and identification of novel lead compounds targeting P. aeruginosa, an opportunistic human pathogen. Graphical abstract

Revision of the genera Cyphonethes Verhoeff, 1926 and Titanethes Schioedte, 1849 (Isopoda: Oniscoidea: Trichoniscidae) with a description of a new genus and three new taxa

A taxonomic study of two troglobite genera resulted in remarkable changes to their composition and our perception of their relationship. The genus Titanethes is treated as monotypic, with one newly described taxon, Titanethes albus matovici n. ssp. One species is transferred from Titanethes to the genus Cyphonethes, Cyphonethes biseriatus (Verhoeff, 1900) comb. nov. A species and a genus are synonymized, Microtitanethes licodrensis syn. nov. The diagnosis of the genus Cyphonethes is amended and revised using comparative morphology of adult males. A new species, Cyphonethes tajanus n. sp, is described. A close relationship between the genera Titanethes and Spelaeonethes is established. Cetinjella monasetrii n. g., n. sp, is described as a new genus and species close to the genus Cyphonethes. It is assumed to be a higropetric cave inhabitant, based on its pereopode structure, with elongated fused dactylus and unguis, and partly by its slightly modified mouthparts. Unique water uptake (for the water conducting system) by the dorsal surface of the frontal pereionite is also assumed for the species, based on the presence, distribution and orientation of specific small scales. The presence and structure of male tergal glands in the genus Tithanethes are treated as taxonomically irrelevant.

A new troglobiotic species, Alpioniscus (Illyrionethes) iapodicus n. sp. (Crustacea: Oniscidea: Trichoniscidae), from Lika region, Croatia

Bedek, J., Horvatović, M. & Karaman, I. M.: A new troglobiotic species, Alpioniscus (Illyrionethes) iapodicus n. sp. (Crustacea: Oniscidea: Trichoniscidae), from Lika region, Croatia. Nat. Croat., Vol. 26, No. 2, 205-214, 2017, Zagreb. Alpioniscus (Illyrionethes) iapodicus n. sp. is described and illustrated. Representing the 14th nominal species of the subgenus Illyrionethes from the Dinaric karst, it is a troglobiotic species collected from the caves in the central part of the Lika region, Croatia. The new species belongs to the strasseri group. Morphological characters differentiating A. iapodicus from other strasseri group representatives are discussed.

A bryozoan species may offer novel antioxidants with anti-carbon-dioxide anion radical activity

The antiradical activity of the freshwater bryozoan Hyalinella punctata water extracts (two samples, seasonal collection) was evaluated by using electron paramagnetic resonance spectroscopy against hydroxyl (√OH), superoxide anion (√O2− ), methoxy (√CH2OH), carbon-dioxide anion (√CO2− ), nitric-oxide (√NO) and 2,2-diphenyl-1-picrylhydrazyl (√DPPH) radicals. The extracts reduced the production of all tested radicals but to a varying degree. The better activity was observed against √CO2− and √CH2OH radicals (54 ± 5% and 44 ± 4%, and 58 ± 6% and 22 ± 2%, respectively) than towards √DPPH, √NO, √OH and √O2− radicals (59 ± 6% and 1.0 ± 0.1%, 46 ± 5% and 14 ± 1%, 7.0 ± 0.5% and 34 ± 3%, and 33 ± 3% and 0%, respectively). FTIR spectra of the both extracts indicate the presence of cyclic peptides and polypeptides which might be responsible for the observed activity. According to the experimental data obtained, H. punctata water extract may be considered as a novel promising resource of natural products with anti √CO2− radical activity.