Assessment of the Effects of Double-Stranded RNAs Corresponding to Multiple Vitellogenesis-Inhibiting Hormone Subtype I Peptides in Subadult Female Whiteleg Shrimp, Litopenaeus vannamei

Vitellogenesis-inhibiting hormone (VIH) negatively regulates reproduction in shrimp and other decapod crustaceans. In order to assess the effects of transcriptional silencing by multiple VIH subtype I sinus gland peptides (SGPs) on ovarian maturation in female whiteleg shrimp, Litopenaeus vannamei, we synthesized five dsRNAs targeting Liv-SGP-A, −B, −C, −F, and −G and injected them into subadults. The following treatments were employed: sgpG-dsRNA (targeting Liv-SGP-G), sgpC-dsRNA (targeting Liv-SGP-C), and mixed-dsRNA (targeting Liv-SGP-A, −B, and −F). The expression of Liv-SGP-G in eyestalks was significantly decreased at 10, 20, and 30 days after the injection of sgpG-dsRNA In addition, it was significantly decreased at 10 and 30 days after the injection of mixed-dsRNA. The expression of vitellogenin (Vg) gene expression in the ovaries, and concentrations of Vg protein in the hemolymph, were not changed by the administration of any dsRNA treatment (the ovaries remained immature in all treated individuals and contained mostly oogonia and previtellogenic oocytes). Although the administration of dsRNAs corresponding to multiple VIHs did not promote ovarian maturation, this is the first report of the co-transcriptional repression of Liv-SGP-G by the injection of dsRNA for homologous genes (Liv-SGP-A, −B, and −F). These results indicate that subadults can respond to the techniques of transcriptional silencing.

An abnormal rostrum in a wild subadult shrimp Farfantepenaeus duorarum (Burkenroad, 1939) (Decapoda, Penaeidae) from the southern Gulf of Mexico

An abnormal bifid rostrum is reported for the first time for a wild-caught subadult female (carapace length = 22.5 mm) of the pink shrimp Farfantepenaeus duorarum (Burkenroad, 1939) from Celestun lagoon, Yucatan, southern Gulf of Mexico. A review of registers on morphological abnormalities in shrimps of the family Penaeidae is provided.

The first record of Montagu’s Harrier Circus pygargus (Aves: Accipitridae) in West Bengal, India

One Montagu’s Harrier Circus pygargus subadult female was identified and photographed in December, 2019 in West Bengal, India. This is the first record from the state.

Evidence of breeding activity of subadult Turdus thrushes in Argentina

Little is known about the age at which many Neotropical bird species first attempt to breed. We evaluated the breeding condition of 515 adult and subadult males and females among four species of Turdus thrushes (T. nigriceps, T. chiguanco, T. amaurochalinus and T. rufiventris) in Tucumán, Argentina during three breeding seasons (2015 to 2018). We registered a total of 126 individuals with brood patches and cloacal protuberances, which accounted for 24.5% of thrushes in breeding condition that we sampled. Forty thrushes had a brood patch (31.7% of those in breeding condition), of which 11 were subadults (8.7%). Eighty-six thrushes (68.3%) had a swollen cloacal protuberance, 18 of which were subadults (14.3%). Only a few of the subadults in breeding condition built nests, incubated eggs or raised nestlings. Of 130 nests we found, only 3 belonged to a subadult thrush (in all cases, a subadult female with an adult social mate), one of which was successful. Further research on these patterns among various Neotropical bird species could lead to important insights into the life history strategies that characterize different populations, and how these ultimately affect their population dynamics.

Transfer of the Namibian Argistes africanus Simon, 1910 (Araneae: Liocranidae) to Afroceto Lyle & Haddad, 2010 (Trachelidae), with a new synonym

Only a single species of the trachelid spider genus Afroceto Lyle & Haddad, 2010 has been recorded from Namibia to date, A. arca Lyle & Haddad, 2010. Examination of the holotype of Argistes africanus Simon, 1910 (Liocranidae), a subadult female specimen, indicates that the species is misplaced and is hereby transferred to Afroceto as A. africana (Simon, 1910) comb. nov. Comparison of the holotype with material of Afroceto arca indicates that this latter species is a junior synonym of A. africana. New records of A. africana from South Africa and Namibia are provided, together with an updated distribution map.

A new minute species of Pristimantis (Amphibia: Anura: Craugastoridae) with a large head from the Yanachaga-Chemillén National Park in central Peru, with comments on the phylogenetic diversity of Pristimantis occurring in the Cordillera Yanachaga

We describe a new minute species of the genus Pristimantis, P. boucephalus sp. nov., from the Yanachaga-Chemillén National Park, Región Pasco, Peru. The description is based on a freshly collected male specimen found at 2950 m a.s.l. in a cloud forest and four previously unidentified museum specimens consisting of two adult males, one subadult female and a juvenile from the Yanachaga-Chemillén National Park. The new species is mainly characterized by a snout–vent length of 13.4–14.5 mm in adult males (n = 3), and 12.5 mm in the only known subadult female, and is compared morphologically and genetically with other taxonomically and biogeographically relevant species of Pristimantis. The new species is characterized by its small size, disproportionally large head with short snout, absence of a tympanic annulus and membrane, and reddish-copper iris. Phylogenetically it belongs to a speciose clade, an as yet unnamed species group, comprising both montane (Andes, Guiana Shield) and lowland (Amazon) taxa from the northern part of South America. The new species is genetically close to the sympatric P. cruciocularis. Species of Pristimantis occurring in the Cordillera Yanachaga region in the Andes of central Peru are members of six divergent phylogenetic lineages.

New record and range extension of the Horned Toad, Rhinella ceratophrys (Boulenger, 1882) (Anura: Bufonidae), in Venezuela, and confirmation of its presence in Brazil

The Horned Toad, Rhinella ceratophrys, is widely distributed in the northwestern part of the Amazon region. It is known from Venezuela by only a single juvenile from the base of Cerro Marahuaca, Amazonas state. Herein we report four additional specimens from Venezuela: three juveniles also from Cerro Marahuaca, and a subadult female from the southern slopes of Cerro La Neblina, at the southern border of Amazonas state. The specimen from Cerro La Neblina extends the species distribution to the extreme south of Venezuelan Amazonia, 307 km south of Marahuaca, and it represents the southeasternmost record of the species. We also confirm the presence of R. ceratophrys in Brazil based on voucher specimens, and present an updated distribution map.