Aniara sepulchralis
Creators: name: Silva, Ruan Felipe da
name: Brito, Rodrigo de Oliveira
name: Martins, Ivan Carlos Fernandes
name: Campos, Lourival Dias
name: Mello, Marcello Neiva de
name: Pearson, David Leander
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Carabidae
Aniara
Aniara sepulchralis

description: RESULTS AND DISCUSSION
General description
The species is entirely black in color with a body length ranging from 11.3 to 12. 8 mm, and an overall fusiform shape and body proportion approximately three times longer than broad.The cuticle is heavily sclerotized with a rough elytral surface (Figs. 14-18).
Head
Rectangular head, broader than long, forehead occupying almost all head space and with two frontal grooves protruding near the orbits and reaching the labral suture (Fig. 9). Two supraorbital bristles on each side with distinct punctuation, the bristle being at the apex longer than the other. Flat clypeus, partially fused to the front, separated only by a weak suture, compound eyes, laterally fitted to the head (Figs. 1-2).
Sub-rectangular labrum, broader than long with distal teeth with either rounded or triangular shapes and 4 bristles between the teeth (Figs. 1-2).
Robust mandibles, longer than broad and concave ventrally; right mandible with molar region consisting of three sinuous teeth at the apex of the inner region, left mandible with two robust and larger teeth than the right at the apex, and two teeth at the base, one larger and another smaller than at the apex (Figs. 1-2).
Unsegmented galea, with rounded apex composed of palpi and with licinia composed of thick bristles on the inner margin.
Segmented antennae with 11 antennomers; scape longer than the other segments, and with two bristles at the apex; short pedicel, rounded and without any bristles; 3-4 antennomers larger than pedicel, with antennomere 3 greater than 4, both have two bristles; 5-11 antennomers steadily smaller in size as they approach the apex, the 5 th largest of these antennomers, and all have a large number of small bristles (Figs. 7-8).
Thorax
Sub-square pronotum, slightly convex, corrugated microsculpture, wider anteriorly and posteriorly, elevations on the lateral side, slightly globular slightly curved lateral margins, slightly rounded and short-bristled anterior and posterior angles, small and barely visible scutellum (Figs. 15-18).
Elytra convex, with parallel lateral margins,completely rough surface, distinct punctuations on entire surface, higher concentration near pronotum, completely short and rounded humeral angle and no bristles (Figs. 15-18).
Prothoracic legs large and thin, small trochanter, globose and without bristles. Large femur, largest leg joint, broader in the mid region and tapered towards the apex; longitudinally spaced bristles and in a line toward the apex. Tibia smaller than femur, homogeneously thin from base to apex, longitudinally spaced bristles and lined toward apex where they cluster; two symmetrical spurs at the apex (Figs. 10-13). Proximal tarsus, with first tarsomere larger than the others, 2-3 more globous, 4 smaller than the others, 5 larger than 2-4 with dilated apex, bearing two simple claws; bristles throughout the tarsus,and tarsomeres 1-3 with agglomerated bristles on the inside.
Metathoracic and mesothoracic legs large and thicker than prothoracic legs. Subtriangular femora without bristles. Trochanter a bean-like shape with a slight depression in the convex part. Large femur, wider in the middle region; spaced bristles, fewer in number than other parts, lined vertically toward the apex. Narrow tibia, larger than femur; longitudinally spaced bristles, in four rows, towards the apex, and with two apical spurs. Proximal tarsus with first tarsomere larger than the others and with the presence of bristles; tarsomeres 2-5 practically the same size and with the presence of bristles, tarsomere 5 with dilated apex, carrying two simple claws (Figs. 10-13).
Dimorphism
Sexual dimorphism within Cicindelidae and closely related Carabidae species has been widely studied. Such structures as legs, mouth and wings, distinguish the sexing of animals (Ide, 2007; Martins et al., 2010; Moravec, 2015).
In A.sepulchralis there was no significant difference in the dorsal aspect (body shape and length) between male and female. However, some specific structures, such as the labrum and tarsi, exhibited differences (Figs. 1-4).
The labrum in both sexes has dark coloration, 4 bristles and 5 teeth. However, females have have triangular-shaped teeth and rectilinear labral suture. Males, on the other hand, have a more sinuous shape in both the teeth and the labral suture (Figs. 1-2). Such sexual differences have been observed in several species of Cicindelidae (Martins et al., 2010).
Males and females also present differences in the bristles present in tarsomeres I, II and III. In males there are adhesive bristles on the inside, which are absent in females (Figs. 3-4). This dimorphism is observed in many species of Cicindelidae (Martins et al., 2010). It is thought that these bristles help males grip the females in copulation and subsequent mate guarding.
Morphometry
Some variables that contributed little to variance within the principal component analysis (PCA) were excluded. These non-relevant variables were head length, antenna, tibia of leg 1, thigh of leg 1, femur of leg 1, spur of leg 1 and trochanter of leg 3 (Fig. 5).
After removal of non-relevant variables, the explanation of total variance was near 70% (Fig. 6). The graph shows how relevant each structure is for the analysis, where the red components have the highest contribution. Each component is consistent for the high or low values. The smaller the angle between the variables, the greater the relationship between them.
Although the sample sizes were small, the p values were so significant, we consider them appropriate for cautious biological interpretation. Regarding morphological differences based on the site from which they were collected, the moist significant variables included: head width (p = 0.0014), pronotum width (p = 0.0088), distance between eyes (p = 0.0130), width from the base of the pronotum (p = 0.0176), labral length (p = 0.0214), labral width (p = 0.0273) and spur (p = 0.0858).The specimens from Igarapé-AÇu showed larger sizes than those from Belém (Table 1).
Behavior and microhabitat have been associated with variation within some morphological structures of several species of beetle. Species of the genus Siagona and Carabus showed variation in the body length and in the morphology of the compound eyes (Talarico et al., 2007; Talarico et al., 2011), and Scaphinotus petersi showed a difference in the head and pronotum (Ober & Connolly, 2015) that were correlated with anthropogenic interferences, such as proximity to urbanized environments (Papp et al., 2020). However, both biotic and abiotic factors need to be tested in the future to determine if individuals of A. sepulchralis from the two study areas are associated with these human influences and, if so, which ones.
Significant variables for p =‘***′ 0.01‘**′ 0.05‘*′ 0.1
AUTHORS’ CONTRIBUTIONS: RFS, ICFM: Conceptualization; RFS, ROB, ICFM, LDC, MNM: Methodology, Software, Data curation, Formal analysis, Writing – original draft,Visualization,Investigation;RFS,ICFM,DLP:Writing – review& editing;ICFM:Funding acquisition;ICFM:Supervision.All authors actively participated in the discussion of the results, they reviewed and approved the final version of the paper.
CONFLICTS OF INTEREST:Authors declare there are no conflicts of interest. FUNDING INFORMATION:This research was funded by Conselho Nacional de Desenvolvimento Científico eTecnológia(CNPq)(process 461005/2014-0). ACKNOWLEDGMENTS: We are grateful to Universidade Federal Rural da Amazônia and EMBRAPA Amazônia Oriental for the research area.We would like to thank Dr. Benedito Nunes for the help with the photographs.We also thank the research group Entomologia na Amazônia:da base à aplicação.
Significant variables for p =‘***′ 0.01‘**′ 0.05‘*′ 0.1
The female specimens presented larger body length and morphological structures (Table 2). Significant variables for sexual dimorphism were: Body length (p = 0.0024); head width (p = 0.0118), distance between eyes (p = 0.0142), pronotum length (p = 0.0415), pronotum width (p = 0.0115), labral length (p = 0.0253); and pronotum base width (p = 0.0785).
As observed in other studies, cicindelids/carabids commonly exhibit sexual dimorphism, as in spurs of the first segment of the tarsus (Fuente et al., 2010), antenomers (Benitez, 2013; Fuente et al., 2010) and abdominal segments (Alibert et al., 2001).The female of A.sepulchralis is significantly larger, as in many invertebrates (Gould, 1996). This may be due to factors such as the ability to support the male′s weight during copulation or the need to support more and heavier eggs for increased fecundity (Adams & Funk, 1997; Tammaru et al., 2002). Possible cause(s) of this size dimorphism include a combination of environmental factors, such as humid or dry weather, and anthropogenic factors, such as soil or forest management and increased urbanization near these sites (Benitez, 2013; Papp et al., 2020).
description: Published as part of Silva, Ruan Felipe da, Brito, Rodrigo de Oliveira, Martins, Ivan Carlos Fernandes, Campos, Lourival Dias, Mello, Marcello Neiva de & Pearson, David Leander, 2023, Morphological redescription and morphometry of Aniara sepulchralis (Coleoptera: Cicindelidae) from Northeast Para, Brazil, pp. 1-11 in Papéis Avulsos de Zoologia 63 on pages 3-10, DOI: 10.11606/1807-0205/2023.63.018, http://zenodo.org/record/8135221