Waldir M. Berbel-Filho

Inter- and intra-basin phenotypic variation in two riverine cichlids from northeastern Brazil: potential eco-evolutionary damages of São Francisco interbasin water transfer

Intraspecific morphological variation can be generated by a set of historical and ecological processes, and can be induced by anthropogenic actions. One such activity that has large-scale environmental impacts in freshwater environments is interbasin water transfer. Brazil’s Mid-Northeastern Caatinga freshwater ecoregion is going through an interbasin diversion that will link waters from São Francisco ecoregion with the four major basins of Mid-Northeastern Caatinga. Here, we aimed to evaluate the morphological variation of two cichlids, Cichlasoma orientale and Crenicichla menezesi, from both ecoregions and test, whether this morphological variation is related to historical isolation among basins and/or to local water flow regimes, through mtDNA (cytb) and geometric morphometric approaches. Our results showed, for both species, significant morphological differences among basins. However, the comparisons between genetic and morphological differences among basins were not significant. Additionally, a significant shared morphological pattern between species (body depth and mouth position) among different habitats was found. These results reinforce a potential role of environmental pressures upon fish morphology, possibly through phenotypic plasticity. The evolutionary role of morphological responses in freshwater fish populations—especially in variable environments—is discussed, as well as the potential eco-evolutionary damages that might result from the artificial river connection.

Effects of Pleistocene climatic and geomorphological changes on the population structure of the restricted-range catfish Trichogenes longipinnis (Siluriformes: Trichomycteridae)

Trichogenes longipinnis Britski & Ortega is a narrowly distributed endemic and phenotypically variable catfish from the coastal basins of the Serra do Mar range in southeast Brazil. We examined patterns of mtDNA variation of this species in coastal basins of the Serra do Mar to determine the influences of past climatic and geomorphological processes in connection with the currently isolated basins. Allozyme data were also used to test the hypothesis that the different spotting patterns in the different areas could be the result of cryptic speciation. Regardless of body pigmentation, T. longipinnis specimens from across the basins were found to belong to a single species, but the populations were structured in accordance with the current hydrological watersheds, in four management units across the three distinct basins of its geographic distribution. Thus, the current genetic distribution may be best explained by both marine regressions and orogeny. Based on the low levels of genetic variation and high population structure observed, we suggest that T. longipinnis should be classified as “vulnerable” in the Brazilian red list of threatened fauna. Furthermore, we propose that the headwaters of the Parati-Mirim River basin should be incorporated as an extension of the Bocaina National Park to protect its genetically differentiated lineages.

Occurrence of Octopus insularis Leite and Haimovici, 2008 in the Tropical Northwestern Atlantic and implications of species misidentification to octopus fisheries management

The genus Octopus has been treated as a “catch all” taxon because many species have morphological similarities. To investigate the taxonomic status of the Octopus species in the Tropical Northwestern Atlantic (TNA) and the Tropical Southwestern Atlantic (TSA), we sampled Octopus insularis Leite and Haimovici, 2008 in three areas of the northeastern Brazilian coast, four Brazilian oceanic islands and one island in Western Caribbean, Mexico. Samples of Octopus maya Voss and Solís, 1966 were obtained from the cultivation center of the Universidad Nacional Autónoma de México (UNAM) in Sisal city. Specimens previously identified as Octopus vulgaris Cuvier, 1797 were collected in two regions of southeast Brazil, in an industrial port in Progreso city (southern Gulf of Mexico) and from a fish market in Isla Mujeres, Mexico (Western Caribbean). Molecular species attribution was completed based on morphology of fresh specimens identified by an octopus specialist and then checked against previous identification (cultivation center and GenBank sequences). Molecular analysis of both mitochondrial (cytochrome oxidase I) and nuclear genes (elongation factor-1α), including GenBank data, confirmed that one specimen collected at the Western Caribbean from Mexico and identified as O. insularis, shared the same haplotype of the species from the type locality, indicating the occurrence of this species in the Caribbean Sea. Phylogenetic analyses indicated that 21 GenBank sequences from TNA identified as O. vulgaris grouped within the O. insularis clade and are most likely to be to the latter species. The COI analysis also showed that 18 individuals collected in fishing landings and fish markets, previously identified as O. vulgaris, had the identical haplotype of O. maya collected in the UNAM cultivation center. These results corroborate the misidentification of species in Mexican fisheries. Based on molecular and morphological data we extended the distribution of O. insularis to the TNA and revealed cases of misidentification among the most commercially exploited octopus species in this region.

Headwater Capture Evidenced by Paleo-Rivers Reconstruction and Population Genetic Structure of the Armored Catfish (Pareiorhaphis garbei) in the Serra do Mar Mountains of Southeastern Brazil

Paleo-drainage connections and headwater stream-captures are two main historical processes shaping the distribution of strictly freshwater fishes. Recently, bathymetric-based methods of paleo-drainage reconstruction have opened new possibilities to investigate how these processes have shaped the genetic structure of freshwater organisms. In this context, the present study used paleo-drainage reconstructions and single-locus cluster delimitation analyses to examine genetic structure on the whole distribution of Pareiorhaphis garbei, a ‘near threatened’ armored catfish from the Fluminense freshwater ecoregion in Southeastern Brazil. Sequences of two mitochondrial genes (cytochrome b and cytochrome c oxidase subunit 1) were obtained from five sampling sites in four coastal drainages: Macaé (KAE), São João (SJO), Guapi-Macacu [sub-basins Guapiaçu (GAC) and Guapimirim (GMI)], and Santo Aleixo (SAL). Pronounced genetic structure was found, involving 10 haplotypes for cytB and 6 for coi, with no haplotypes shared between localities. Coalescent-based delineation methods as well as distance-based methods revealed genetic clusters corresponding to each sample site. Paleo-drainage reconstructions showed two putative paleo-rivers: an eastern one connecting KAE and SJO; and a western one merging in the Guanabara Bay (GAC, GMI, and SAL). A disagreement was uncovered between the inferred past riverine connections and current population genetic structure. Although KAE and SJO belong to the same paleo-river, the latter is more closely related to specimens from the Guanabara paleo-river. This discordance between paleo-drainage connections and phylogenetic structure may indicate an ancient stream-capture event in headwaters of this region. Furthermore, all analyses showed high divergence between KAE and the other lineages, suggesting at least one cryptic species in the latter, and that the nominal species should be restricted to the Macaé river basin, its type locality. In this drainage, impacts such as the invasive species and habitat loss can be especially threatening for such species with a narrow range. Our results also suggest that freshwater fishes from headwaters in the Serra do Mar mountains might have different biogeographical patterns than those from the lowlands, indicating a complex and dynamic climatic and geomorphological history.

First record of a male of Kryptolebias hermaphroditus Costa, 2011 (Cyprinodontiformes: Cynolebiidae)

During an ichthyological survey in September 2015 at the Ceara-Mirim River estuary, Rio Grande do Norte State, northeastern Brazil, we collected a male of Kryptolebias hermaphroditus , a cynolebiid species that had been previously described as containing exclusively self-fertilizing hermaphrodites. This is the first record of a male in this species, over 140 years after the discovery of the mangrove rivulid species from Brazil. Our discovery reinforces the need for more studies in K. hermaphroditus , as well as the potential of this species as a model for evolutionary studies due to its unique mating system.

New records and distribution extension of Hyphessobrycon itaparicensis Lima & Costa, 2001 (Characiformes: Characidae) in coastal drainages of Sergipe State, northeastern Brazil

The present study reports the first record of the small characid fish Hyphessobrycon itaparicensis Lima and Costa, 2001 in two coastal drainages of Sergipe State, Brazil. This species was collected in three sampling sites from Piaui and Sergipe river basins, both in the hydrographic ecoregion of Northeastern Mata Atlantica. Aspects of habitat, diet composition, phenotypic variation, molecular identification and distribution of H. itaparicensis are herein discussed.

Updated checklist and DNA barcode-based species delimitations reveal taxonomic uncertainties among freshwater fishes from the mid-north-eastern Caatinga ecoregion, north-eastern Brazil

The mid-north-eastern Caatinga is a semiarid freshwater ecoregion in North-eastern Brazil that is dominated by temporary rivers and is currently classified as one of the least ichthyologically-known ecoregions in the world. The present study aimed to provide an updated checklist of mid-north-eastern Caatinga ecoregion (MNCE) freshwater fish species and evaluate their taxonomic identity using morphology, DNA barcoding and multiple species delimitation approaches. After reviewing published studies and ichthyological collections, 119 species were identified. Among these were 94 putatively valid native and 14 non-native species, five undescribed native species, four new records for the MNCE, 11 potential cases of misidentification and 14 species listed as inquirenda. Additionally, 252 individuals from 49 species were barcoded, revealing three potential taxonomic synonyms. The combined molecular approaches estimated a total of 91 native species, although a finalized species list for the MNCE awaits additional taxonomic revisions and field surveys. This study provides the most up-to-date species checklist for the MNCE and a molecular reference database for identifying MNCE fishes with DNA barcodes. Results highlight the need to integrate traditional taxonomy with molecular approaches to correctly identify species, especially in taxonomically problematic ecoregions such as the MNCE.

Ultrasensitive environmental assessment of xeno-estrogens in water samples using label-free graphene immunosensors

There is a growing interest in the possible environmental health impact posed by endocrine-disrupting chemicals (EDCs). A challenge to the field of endocrine disruption is that these substances are diverse and may not appear to share any structural similarity other than usually being low molecular mass (<1000 Da) compounds. Here we demonstrate the effectiveness of sensor device for the detection of low molecular weight, poorly water soluble, estrogenic compounds E1, E2 and EE2, fabricated by electropolymerization over graphene screen printed electrode (SPE). The PANI/Gr-SPE-devices displayed linear responses to estrogenic substances, in EIS assays, from 0.0975 ng/L to 200 ng/L in water samples, with a detection limit of 0.043 pg/L for E1, 0.19 ng/L for E2 and 0.070 pg/L for EE2 which is lower than other current biosensing techniques. This portable, disposable immunosensor offers a solution for immediate measurement at sample collection sites, due to its excellent sensitivity and selectivity when testing water samples obtained directly from rivers and waste water treatment facilities. The simple screen printing production method will enable the low cost, high volume production required for this type of environmental analysis.