Molossus melini Montani et al., 2021

Olimpio, Ana Priscila Medeiros, Lima, Amanda Cristiny da Silva, Mendes, Samira Brito, Natividade, Beatriz Dybas da, Fraga, Elmary da Costa, Barros, Maria Claudene & Sampaio, Iracilda, 2024, Molossus melini Montani et al. 2021 (Chiroptera, Molossidae) in Brazil: new insights for distribuition, morphology and genetics, Biodiversity Data Journal 12, pp. 114261-114261 : 114261

Molossus melini Montani et al., 2021

Materials

Type status: Other material. Occurrence: individualCount: 1; sex: female; lifeStage: adult; preparations: skin | skull | tissue (70% alcohol); photograph; DNA; associatedSequences: OR143786; occurrenceID: 860E0771-0BD9-57E5-A5C3-E0E8EC00533F; Taxon: scientificName: Molossus melini Montani et al., 2021; kingdom: Animalia ; phylum: Chordata ; class: Mammalia ; order: Chiroptera ; family: Molossidae ; genus: Molossus ; specificEpithet: melini; taxonomicStatus: accepted; Location : continent: America ; country: Brazil; stateProvince: Paraná; municipality: Curitiba ; Event : year: 2020; month: 11; day: 05; Record Level : institutionID: Mammal Collection of Federal University of Paraná; institutionCode: DZUP/CCMZ 2336; basisOfRecord: PreservedSpecimen Type status: Other material. Occurrence: individualCount: 1; sex: female; lifeStage: adult; preparations: skin | skull | tissue (70% alcohol); photograph; DNA; associatedSequences: OR240233; occurrenceID: CAF91EE7-1352-5856-AAB7-1DE8E1FE01D4; Taxon: scientificName: Molossus melini Montani et al., 2021; kingdom: Animalia ; phylum: Chordata ; class: Mammalia ; order: Chiroptera ; family: Molossidae ; genus: Molossus ; specificEpithet: melini; taxonomicStatus: accepted; Location : continent: America ; country: Brazil ; stateProvince: Parana ; municipality: Curitiba ; Event : year: 2020; month: 11; day: 21; Record Level : institutionID: Mammal Collection of Federal University of Parana ; institutionCode: DZUP/CCMZ 2337; basisOfRecord: PreservedSpecimen Type status: Other material. Occurrence: individualCount: 1; sex: female; lifeStage: adult; preparations: skin | skull | tissue (70% alcohol); photograph; DNA; associatedSequences: OR144072; occurrenceID: 06575217-4228-5CBD-8094-CB152F9D4B90; Taxon: scientificName: Molossus melini Montani et al., 2021; kingdom: Animalia ; phylum: Chordata ; class: Mammalia ; order: Chiroptera ; family: Molossidae ; genus: Molossus ; specificEpithet: melini; taxonomicStatus: accepted; Location : continent: America ; country: Brazil ; stateProvince: Parana ; municipality: Curitiba ; Event : year: 2020; month: 11; day: 10; Record Level : institutionID: Mammal Collection of Federal University of Parana ; institutionCode: DZUP/CCMZ 2338; basisOfRecord: PreservedSpecimen Type status: Other material. Occurrence: individualCount: 1; sex: male; lifeStage: adult; preparations: skin | skull | tissue (70% alcohol); photograph; DNA; associatedSequences: OR144071; occurrenceID: 9E536082-BEBA- 5AD 0-947E-4238EFA59E70; Taxon: scientificName: Molossus melini Montani et al., 2021; kingdom: Animalia ; phylum: Chordata ; class: Mammalia ; order: Chiroptera ; family: Molossidae ; genus: Molossus ; specificEpithet: melini; taxonomicStatus: accepted; Location : continent: America ; country: Brazil ; stateProvince: Parana ; municipality: Curitiba ; Event : year: 2020; month: 02; day: 03; Record Level : institutionID: Mammal Collection of Federal University of Parana ; institutionCode: DZUP/CCMZ 2339; basisOfRecord: PreservedSpecimen

Diagnosis

The M. melini specimens displayed a dorsal and ventral fur measuring 4 mm in length, each adorned with two colour bands. The colouration of the dorsal fur's base occupied 1/4 of its length, while, for the ventral fur, the base colour covered 1/5 of the fur. The variations in colouration amongst the M. melini specimens are detailed as follows: DZUP/CCMZ 2336 - Dorsal: base is Snow White (code 1) and the tip is Olive Brown (code 109). Ventral: base Snow White (code 1) and the tip is Broccoli Brown (code 108). DZUP/CCMZ 2337 - Dorsal: base is Snow White (code 1) and the tip is Wood Brown (code 105). Ventral: base Snow White (code 1) and the tip is Broccoli Brown (code 108). DZUP/CCMZ 2338 - Dorsal: base is Snow White (code 1) and the tip is Yellowish-Brown (code 104). Ventral: base Snow White (code 1) and the tip is Broccoli Brown (code 108) (Fig. 2 F and G). DUZP/CCMZ 2339 - Dorsal: base is Snow White (code 1) and the tip is Olive Brown (code 109). Ventral: base Snow White (code 1) and the tip is Broccoli Brown (code 108).

The specimens exhibited a braincase larger than the rostrum and, in lateral view, the upper incisors converged with pincer-like tips projecting beyond the canines. The infraorbital foramen opened laterally in the rostral view. The basiesphenoid pit was rounded, well-defined and moderately deep, while the mastoid process was slightly directed towards the foramen. The sagittal and lambdoidal crests were poorly developed and the occipital complex had a rounded shape. The nasal process was well-developed and projected over the nasal cavity (refer to Fig. 2 ). For detailed external and cranial measurements of the M. melini specimens, including comparisons with data from Montani et al. (2021) and Pavé et al. (2023), please refer to Table 2 . Ventrally, hairs extend across the wing membranes.

Distribution

Estancia Laguna San Carlos, approximately 10 km south of Melincué, General López Department, Santa Fe Province, Argentina (33°45'3.5"S; 61°24'25.2"W; 90 m elev.) ( Montani et al. 2021). Entre Rios Province, Parana Department, Parana City, Argentina (-31.747, -60.522; 77 m elev.) ( Pavé et al. 2023).

Biology

Genetic: Molecular analysis revealed a strong clustering of specimens from the present study with M. melini from the Argentine Pampas (GenBank), supported by a 98% bootstrap (refer to Fig. 3 ) and a posterior probability of 1 (Suppl. material 1). The average genetic divergence was found to be 1.2%. Notably, when plotting the sequences of the specimens on the BOLD Systems platform, a high level of similarity, ranging from 99.22% to 99.53%, was observed with deposited M. melini specimens. Consequently, this study marks the first record of M. melini for Brazil, extending its distribution more than 1,300 km northeastwards.

Taxon discussion

Molossus melini was initially described by Montani et al. (2021) in the Pampa Region of Argentina, with the type locality identified as Estancia Laguna San Carlos, approximately 10 km south of Melincué, General López Department, Santa Fe Province, Argentina. Pavé et al. (2023) subsequently expanded the distribution of this species by 230 km northeast, documenting its presence in the Espinal Ecoregion of Argentina.

Currently, there is limited knowledge regarding the biology and ecology of M. melini . In this study, we contribute to the understanding of this species by documenting its occurrence, marking the first record in Brazilian territory. This discovery extends its distribution more than 1,300 km northeastwards. Our research delves into external and cranial morphology, as well as genetic aspects of M. melini . Prior to our study, seven Molossus species were documented in Brazil: M. rufus , M. molossus , M. coibensis , M. aztecus , M. currentium , M. fluminensis and M. pretiosus ( Garbino et al. 2022).

Montani et al. (2021) highlighted morphological characters, such as orange colouration and specific cranial and body measurements, for the identification of M. melini . Subsequently, Pavé et al. (2023) emphasised the significance of orange colouration, forearm length (> 41 mm) and a combination of measurements as useful identification criteria. In our study, M. melini specimens exhibited forearm lengths ranging from 39.9 to 40.08 mm, slightly smaller than reported in the literature. Dorsal colouration presented two bands, a Snow White base colour and apex colours ranging from Olive Brown, Broccoli Brown, Wood Brown to Yellowish-Brown. This variation may be associated with a latitudinal gradient, a phenomenon observed in other mammals ( Bogdanowicz 1990, Storz et al. 2001, Watt et al. 2010, Clauss et al. 2013).

Montani et al. (2021) suggested that M. melini shares overlapping measurements only with M. alvarezi and M. currentium . However, our research reveals morphological variation in forearm size that overlaps with that of other species, M. aztecus , M. bondae , M. milleri , M. molossus and M. verrilli , posing challenges for species identification. In the specimens of M. melini analysed, we observed that, ventrally, hairs extend across the wing membranes, a characteristic that is less evident in other species within the genus.

Furthermore, we observed that some diagnostic cranial characteristics of the species diverged when compared to the original description. Our specimens exhibited a less developed sagittal crest and lambdoidal crest and a rounded occipital complex, in contrast to the findings of Montani et al. (2021), who observed a triangular occipital complex in posterior view and well-developed sagittal and lambdoidal crests. It is important to note that few individuals have been analysed in the aforementioned studies, highlighting the need to include more specimens to understand the diagnostic characters of the species. It is worth noting that, morphologically, many species within Molossus are highly similar, complicating the identification and delimitation of species, as noted by Loureiro et al. (2018).

Genetic data indicate low intraspecific variation (1.2%) and a robust clustering of M. melini specimens from Brazil with those from the Pampa Region of Argentina. Additionally, when plotted in the BOLD Systems database, they exhibited high similarity ranging from 99.22% to 99.53% with M. melini specimens. This study contributes to documenting the occurrence of M. melini in Brazil, marking the third known locality and the first in Brazilian territory. It provides valuable insights into the distribution, morphology, morphometrics and genetics of this species.

Figures

Figure 2. Female specimen of Molossus melini (DZUP / CCMZ 2338) from Brazil, Curitiba, PR, Atlantic Forest. Views of the skull: A Superior; B Inferior, the arrow indicates the basiesphenoid pit; C Lateral, the arrows show the poorly-developed sagittal crest and well-projected incisors; D Posterior, the arrow shows the rounded shape of the occipital complex; E Frontal, highlighting the convergent incisors with the pincer-like tips; F, G Specimen's skin dorsal and ventral view respectively. Scale of 2 mm.

Figure 3. Maximum Likelihood for species of the genus Molossus, based on 657 base pairs of the mitochondrial gene COI: The analysis focuses on highlighting specimens of Molossus melini from Brazil and Argentina. The values displayed on the branches represent the bootstrap values, with only those exceeding 80 % being shown.