Bedbugs Evolved before Their Bat Hosts and Did Not Co-speciate with Ancient Humans

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Genome‐wide search for leech antiplatelet proteins in the non‐blood‐feeding leech Helobdella robusta (Rhyncobdellida: Glossiphoniidae) reveals evidence of secreted anticoagulants

The genome of the non‐blood‐feeding glossiphoniid leech Helobdella robusta was screened for leech antiplatelet protein (LAPP), an anticoagulant that specifically inhibits collagen‐stimulated platelet aggregation. Previously identified LAPP sequences from Haementeria officinalis were used as queries against the predicted genes in the genome, employing a variety of BLAST protocols. Matches were reciprocally BLASTed against GenBank databases as a cross‐validation of the predicted annotations of the genes. A total of eight loci, positioned as a tandem array, were recovered with significantly low e‐values; these showed high sequence similarity (32.49% average sequence similarity of shared amino acid positions) to the known anticoagulants. Moreover, six of these possessed a predicted signal‐peptide toward the N‐terminus, indicating their secretion by the leech. All eight loci, together with known LAPP sequences from Ha. officinalis, as well as several sequences from publicly available expressed sequence tag libraries of Ha. depressa and He. robusta, were aligned and subjected to phylogenetic analysis. The resulting tree showed a monophyletic clade consisting of the He. robusta loci, which was sister to a clade comprised of Haementeria‐derived sequences. To corroborate the evolution of the anticoagulants with the evolution of leeches more generally, the topology of the LAPP‐tree was compared to that of a previously published leech phylogeny; these showed compatible topologies with respect to the included genera. These results corroborate recent phylogenetic work, which suggests that this non‐blood‐feeding leech has a hematophagous ancestry.     

Ecological interaction of a “parasitic” candiru catfish and botos (Inia geoffrensis)

The range of ecological interactions of the boto (Inia geoffrensis), an obligate freshwater dolphin of South America, is poorly known. We describe a new interaction between botos and small candiru catfish (genus Ochmacanthus), and their possible relationships. Candirus were photographed on at least 29 different botos. The minimum number of candirus per boto varied greatly from 1 to >230 (mean = 16.3, SD = 39.4, mode = 1). Our observations showed that candiru‐boto interactions occur commonly year‐round. Two types of ecological interaction may be occurring: parasitism (trophic) or phoresy (nontrophic). Although candirus are generally known as parasites, the candiru‐boto relationship does not appear to fulfill several characteristics of a typical parasitic interaction. Thus, the candiru‐boto relationship is most likely phoretic in nature. A shift in candiru trophic strategy may occur depending on the victim (botos or fish) and on the spatial scale, and human activities may influence the nature of these complex ecological interactions.     

A new candiru of the genus Paracanthopoma (Siluriformes: Trichomycteridae) from the Araguaia River basin,central Brazil

A new species of the candiru genus Paracanthopoma is described from the floodplains of the Bananal Island, a transition area between the Cerrado and Amazon, in the Araguaia River basin, central Brazil. Paracanthopoma cangussu sp. nov. is distinguished from its congeners, Paracanthopoma parva and Paracanthopoma saci, by the presence of seven opercular odontodes, five dentary teeth, five median premaxillary teeth, and first dorsal-fin pterygiophore in a vertical through the centrum of the 23th or 24th vertebra. It is further distinguished from each congener by an exclusive combination of character states, comprising the number of vertebrae, number of precaudal vertebrae, number of dorsal procurrent caudal-fin rays, number of ventral procurrent caudal-fin rays, number of dorsal-fin rays, disposition of pores on the cephalic portion of the latero-sensory system, absence of an anterior process on the anterior margin of parieto-supraoccipital, number of dorsal-fin pteryigiophores and number of interopercular odontodes. Although vandelliines are known for being exclusively hematophagous, with guts gorged with blood, two cleared and stained specimens of P. cangussu sp. nov. had Chironomidae larvae (Insecta) on their guts. Because most specimens of P. cangussu sp. nov. were collected with stomachs filled with blood, it was hypothesized that the species feeds accidentally or occasionally on insects.     

The sound of a blood meal: Acoustic ecology of frog‐biting midges (Corethrella) in lowland Pacific Costa Rica

Animal communication systems are often exploited by eavesdropping antagonists, especially predators and ectoparasites. Female frog‐biting midges (Diptera: Corethrellidae) are known to use male anuran advertisement calls to locate their blood hosts, frogs. Here, we use acoustic midge traps broadcasting synthetic and recorded calls to identify those frog call parameters that affect midge attraction. At our study site in Pacific lowland Costa Rica, we found that overall midge attraction was influenced by both spectral and temporal acoustic parameters. Low dominant frequencies (below 1 kHz) and short pulse durations (between 125 and 500 ms) attracted the highest numbers of midges in tests with synthetic sinusoidal pure tones. These preferences partially explained the relative attractiveness of the advertisement calls of ten local frog species. The advertisement calls of the common and widespread Giant Bullfrog, Leptodactylus savagei (Anura: Leptodactylidae), attracted by far the largest number of midges, suggesting that this frog species might be a key resource for frog‐biting midges in Costa Rica. Although we found that calls of different frog species attracted different midge species/morphospecies in statistically different proportions, acoustic niche differentiation among midge species appeared to be moderate, suggesting either a limited degree of host specialization or the use of additional short‐range, that is, chemical, host recognition cues.