Notes on some Late Cretaceous goniasterid starfish (Echinodermata, Asteroidea) from Belgium and Germany

Both partially articulated specimens and dissociated marginal ossicles form the basis for erection of two new species of Late Cretaceous goniasterids from the Mons and Liège-Limburg basins (Belgium) and the Hannover area (Germany). Chomataster breizh sp. nov., which recalls the type species, Chomataster acules Spencer, 1913, but differs in several respects, is based on a partial external mould of the marginal frame of disc and arms in flint (upper Campanian Spiennes Chalk Formation; Mons Basin), as well as on a more or less complete individual, preserving small, spherical spines and granules and encased in a flint nodule from the upper Maastrichtian Nekum Member (Maastricht Formation; Liège-Limburg Basin). In Ch. breizh sp. nov., supero- and inferomarginals bear close-set granule pits, of varying sizes, as well as bivalved alveolar scars of pedicellariae; median superomarginals and all inferomarginals lack large, crater-shaped spine pits – such are found only in the disc/arm transition and along the arms. Dissociated supero- and inferomarginal ossicles from the lower and upper Campanian of the Hannover area and the upper Campanian of northeast Belgium, previously recorded either as indeterminate astropectinids or as Nymphaster obtusus (Forbes, 1848) var. nov. and as Nymphaster sp., respectively, here are assigned to Nymphaster mudzborgh sp. nov. This species is characterised by a row of 3–5 large spine pits on the aboral and lateral surfaces of superomarginals; inferomarginals have an angular profile and a close cover of granule pits. Nymphaster tethysiensis Villier, 2001, from the upper Campanian of Landes (southwest France; Villier and Odin, 2001) appears best accommodated in Chomataster as well, because in the arm superomarginals alternate rather than meet over the mid-radial line.

Taxonomic revision of the new spider genus Hortophora, the Australasian Garden Orb-weavers (Araneae, Araneidae)

The new genus Hortophora in the orb-weaving spider family Araneidae Clerck, 1757 is established to include 13 species from the Australasian-Pacific region, with ten species known from Australia (five of which new to science): Hortophora biapicata (L. Koch, 1871), comb. nov. (type species) (= Araneus biapicatifera Strand, 1907, syn. nov.; = Epeira frosti Hogg, 1896, syn. nov.); H. cucullussp. nov.; H. lodicula (Keyserling, 1887), comb. nov. (= Epeira scutigerens Hogg, 1900, syn. nov.); H. megacanthasp. nov.; H. porongurupsp. nov.; H. tatianeaesp. nov.; H. transmarina (Keyserling, 1865), comb. nov.) (also known from Papua New Guinea); H. urbana (Keyserling, 1887), comb. nov.; H. walesiana (Karsch, 1878), comb. nov. (= Epeira rhombocephalaThorell 1881, syn. nov.; = Epeira lutulenta Keyserling, 1886, syn. nov.); and H. yesabahsp. nov. The following species of Hortophoragen. nov. are recognised from the Pacific region but not revised in detail due to a lack of material, specifically mature males: Hortophora capitalis (L. Koch, 1871), comb. nov. (removed from synonymy with H. transmarinacomb. nov.) from Fiji, New Caledonia and Vanuatu; H. flavicoma (Simon, 1880), comb. nov. from New Caledonia (incl. Loyalty Islands) and H. viridis (Keyserling, 1865), comb. nov. (removed from synonymy with H. transmarinacomb. nov.) from Samoa. Epeira thyridota Thorell, 1870 is here removed from synonymy with H. transmarinacomb. nov. and transferred to Backobourkia Framenau, Dupérré, Blackledge & Vink, 2010, B. thyridota (Thorell, 1870), comb. nov.Hortophoragen. nov. includes medium-sized to large, nocturnal orb-weaving spiders typically with subtriangular to ovoid abdomen bearing humeral humps. The tibiae of the second leg in males is usually enlarged with numerous strong spines and an apico-ventral megaspur carrying a large spine in some species. Male pedipalps generally have an elongated, transverse median apophysis ending in a bifid tip in most species, a sinuous to straight embolus and a bubble-shaped terminal apophysis. The female epigyne scape is highly elongated and does not have a terminal pocket. Genital mutilation, i.e. breaking off the epigyne scape during copulation, is common in some species. Hortophoragen. nov. include the most frequently collected nocturnal orb-weaving spiders in Australia.

Rediscovery, redescription, and reclassification of the rare and unusual fly Pyrgometopa penicillata Kertész (Diptera: Drosophilidae)

For slightly more than a century only the type specimen has been known for Pyrgometopa penicillata, a monotypic genus of Drosophilidae whose sole species has an ocellar triangle distended into a bizarre tubercle bearing a tuft of large, spine-like bristles in both sexes. Here we report additional specimens of both sexes of the species, recently rediscovered from Brazil, Peru and French Guyana, allowing us to state that Pyrgometopa is a junior synonym for Stegana, a large cosmopolitan genus. A detailed redescription of Stegana penicillata (Kertész) new combination is provided, including new morphological information, like the male and female terminalia, the egg and a short discussion is provided about its hallmark feature.

Two new species of Tomocerus ocreatus group with a single large distal dental spine (Collembola, Tomoceridae)

Most members of Tomocerus ocreatus group have two distal large spines on dens, so far, only Tomocerus spinulus Chen & Christiansen, 1998 and Tomocerus leyensis Yu & Deharveng, 2018 have been described with only one distal large spine and are thus exceptional in this group. In the present paper, we report two other species with the same form. The two new species resemble T. spinulus in chaetotaxy, dental spine formula and general shape of the dental spines, but differ from it in several other characters, including position and shape of the prominent dorsal chaetae on the manubrium and dens. Also, T. pseudospinulus sp. nov. differs from T. spinulus in having larger denticles on the dental spines, and T. paraspinulus sp. nov. differs from T. spinulus in having longer antenna and more chaetae on the tenaculum. The two new species are similar, but can be distinguished by length of the antenna, number of the chaetae on tenaculum, status of the prominent manubrial dorsal chaetae and fine sculpture of the dental spines. Distances of COI mtDNA also support the validation of two new species. A key to species of T. ocreatus species-group with single large dental spine is provided.

Hippocampus japapigu, a new species of pygmy seahorse from Japan, with a redescription of H. pontohi (Teleostei, Syngnathidae)

The pygmy seahorseHippocampusjapapigusp. n.is described based on three specimens, 13.9–16.3 mm SL, collected from a mixed soft coral and algae reef at 11 m depth at Hachijo-jima Island, Izu Islands, Japan. The new taxon shares morphological synapomorphies with the previously described central Indo-Pacific pygmy seahorses,H.colemani,H.pontohi, H.satomiae, andH.waleananus, including extremely small size, 12 trunk rings, strongly raised continuous cleithral ring, snout spine, large spine on the eighth lateral and fifth and 12 superior trunk ridges, respectively, and unusual wing-like-protrusions immediately posterior to the head.Hippocampusjapapigusp. n.can be distinguished from all congeners by the following combination of features in the anterodorsal area of the trunk: bilaterally paired wing-like protrusions formed by a single pair of large, truncate spines projecting dorsolaterad on the first superior trunk ridge, followed by a unique elevated dorsal ridge formed by triangular bony mounds dorsally on the second to fourth superior trunk ridges. In contrast,H.pontohipossesses a pair of large truncate spines projecting strongly laterad on both the first and second superior trunk ridges followed by flat surfaces dorsally on the third and fourth superior trunk rings. The new species can be further differentiated by genetic divergence fromH.pontohi(an uncorrected p-distance of 10.1% in the mitochondrial COI gene) and a striking reticulated white and brown lattice pattern on the head, trunk, and tail.Hippocampusjapapigusp. n.represents the fifth species of pygmy seahorse recorded in Japan.

Morphological comparison of Astropecten cingulatus and a new species of Astropecten (Paxillosida, Astropectinidae) from the Gulf of Mexico

Astropecten cingulatus is a conspicuous species, which displays a large superomarginal plate series on the abactinal surface. Herein we describe a new species from off the Texas coast that shows the superficial appearance of A. cingulatus, including these large superomarginal plates, but with armature differing from that of typological A. cingulatus. This species shows the actinal surface of the inferomarginal plates without the squamules present on A. cingulatus. In addition, the adambulacral plates possessed but a single central large spine surrounded by a circle of spines rather than spine rows. The abactinal paxillar region was also very narrow. Statistical analysis of these and other morphological characters showed the specimens differed significantly from those of A. cingulatus. The regression of the slope of R:SM# vs. R was significant but the intercept was not. Therefore the two species are indistinguishable at small sizes based on R:SM. Compared to known Atlantic Astropecten spp. these observed characters warrant the description of a new species, Astropecten karankawai, for the specimens from off the coasts of Texas and Mexico.

Functional morphology of sexually selected gentalia in the water strider Aquarius remigis

In the water strider Aquarius remigis (Say), sexual selection favours males with longer genitalia. We used video analysis plus light and scanning electron microscopy to examine the structure, movement, and articulation of the genitalia as a first step in determining the functional basis of this selection. Male A. remigis are characterized by long, robust genital segments; a marked ventral median notch in the posterior margin of the pregenital segment; an enlarged phallus tipped with a uniquely prolonged sclerotized plate; and a large, spine-covered, membranous lobe that inflates within the female's reproductive tract. Detailed examinations of genital interactions prior to and during copulation allow us to deduce the functional significance of these distinguishing traits. We postulate that by increasing the length, mobility, strength, and rigidity of the phallus, the first three traits increase the ability of males to achieve intromission in spite of active female resistance, and to maintain intromission during the prolonged copulations characteristic of this species. Inflation of the large, spinous lobe probably contributes to the latter function, and may also directly affect fertilization success by displacing or damaging sperm from previous males. We discuss these interpretations in the context of current theories of genitalic coevolution and sexual conflict in the Gerridae.

A reappraisal of the taxonomic position of Enhydrosoma curvirostre (Copepoda: Harpacticoida: Cletodidae)

Enhydrosoma curvirostre is redescribed from archived and new material with particular attention to the structure of the mouthparts and other details of the fine structure not previously reported. It is shown that the species cannot be maintained in Enhydrosoma but is more closely related to Cletodes, the genus in which the original author placed it. However, it is shown that the species must be assigned to a new genus, Spinapecruris, as a result of possessing autapomorphies on the maxillule (only seven setae on the basis), thoracopods 2–4 (a large spine on the distal margin) and possibly the caudal ramus (proximal insertion of seta VII) and lacking apomorphies which may define Cletodes.