Tropical Fauna Research Articles

Diversity partitioning in Permian and Early Triassic benthic ecosystems of the Western USA: a comparison

This paper compares the relative contributions of within-habitat diversity [alpha-diversity] and between-habitat-diversity [beta-diversity] to regional diversity [gamma-diversity] in marine benthic communities of the western US before and after the end-Permian mass extinction. We found that presumably cool-water faunas from the Permian Gerster Limestone and the Park City Formation had low alpha- and beta-diversities, comparable to those of low diverse faunas of the Early Triassic. In contrast, tropical Permian faunas had much higher alpha-diversities and a variable pattern of beta-diversity: Whereas faunas of space-limited bioherms show a positive correlation between beta-diversity and gamma-diversity, beta-diversity in level-bottom faunas is elevated only when gamma-diversity is very high (>250 species). This contrasting pattern probably reflects differential effects of interspecific competition on habitat partitioning. In low-competitive level-bottom faunas, species are able to coexist until competition forces species into their ecological optima, thereby increasing beta-diversity. This effect occurs at much lower gamma-diversities in more competitive reef-bound faunas, causing the observed positive correlation between beta- and gamma-diversity. We suggest that differences in the level of interspecific competition and hence diversity partitioning between Permian and Triassic benthic communities result from the higher average metabolic rates in the Mesozoic mollusc-dominated benthos in contrast to their Permian counterparts.

ZOO INDONESIA: SUATU STUDI INFORMETRIKA

This study aims to determine the development of Tropical Fauna Journal Zoo Indonesia which includes article distribution, patterns of authorship and fauna research subject at issue in 1983-2014. This study uses informetrics analysis of all articles in the journal. The results showed: (1) the distribution of articles on every volume published by Zoo Indonesia have increased with the last number is six articles on each volume to its publication; (2) authorship patterns show the dominant by single author of 46,08%; and (3) research subjects that most discussed is about arthropods amounted to 30,41%. The conclusion is Zoo Indonesia on his way continuously tries to improve its quality as a scientific journal by a system of e-journal and also continue to fix both physically and editorial system aspects in it.

Phylogeography of the Subgenus Drosophila (Diptera: Drosophilidae): Evolutionary History of Faunal Divergence between the Old and the New Worlds

The current subgenus Drosophila (the traditional immigrans-tripunctata radiation) includes major elements of temperate drosophilid faunas in the northern hemisphere. Despite previous molecular phylogenetic analyses, the phylogeny of the subgenus Drosophila has not fully been resolved: the resulting trees have more or less varied in topology. One possible factor for such ambiguous results is taxon-sampling that has been biased towards New World species in previous studies. In this study, taxon sampling was balanced between Old and New World species, and phylogenetic relationships among 45 ingroup species selected from ten core species groups of the subgenus Drosophila were analyzed using nucleotide sequences of three nuclear and two mitochondrial genes. Based on the resulting phylogenetic tree, ancestral distributions and divergence times were estimated for each clade to test Throckmorton’s hypothesis that there was a primary, early-Oligocene disjunction of tropical faunas and a subsequent mid-Miocene disjunction of temperate faunas between the Old and the New Worlds that occurred in parallel in separate lineages of the Drosophilidae. Our results substantially support Throckmorton’s hypothesis of ancestral migrations via the Bering Land Bridge mainly from the Old to the New World, and subsequent vicariant divergence of descendants between the two Worlds occurred in parallel among different lineages of the subgenus Drosophila. However, our results also indicate that these events took place multiple times over a wider time range than Throckmorton proposed, from the late Oligocene to the Pliocene.

Elevational sensitivity in an Asian 'hotspot': moth diversity across elevational gradients in tropical, sub-tropical and sub-alpine China.

South-western China is widely acknowledged as a biodiversity ‘hotspot’: there are high levels of diversity and endemism, and many environments are under significant anthropogenic threats not least climate warming. Here, we explore diversity and compare response patterns of moth assemblages among three elevational gradients established within different climatic bioregions - tropical rain forest, sub-tropical evergreen broad-leaved forest and sub-alpine coniferous forest in Yunnan Province, China. We hypothesised that tropical assemblages would be more elevationally stratified than temperate assemblages, and tropical species would be more elevationally restricted than those in the temperate zone. Contrary to our hypothesis, the moth fauna was more sensitive to elevational differences within the temperate transect, followed by sub-tropical and tropical transects. Moths in the cooler and more seasonal temperate sub-alpine gradient showed stronger elevation-decay beta diversity patterns, and more species were restricted to particular elevational ranges. Our study suggests that moth assemblages are under threat from future climate change and sub-alpine rather than tropical faunas may be the most sensitive to climate change. These results improve our understanding of China’s biodiversity and can be used to monitor future changes to herbivore assemblages in a ‘hotspot’ of biodiversity.

Multi-scale taxonomic diversity of marine harpacticoids: Does it differ at high and low latitudes?

We used a comprehensive database comprising a worldwide distribution of 3074 species of marine benthic harpacticoid copepods to explore Arctic (north to 60°N) and tropical (32°S–32°N) faunas. In addition to species and genus richness, we compared the number of observed genera with that expected from a neutral model (random samples from a corresponding species pool). This analysis was performed at three scales: global (Arctic vs. tropics), regional (three Arctic and four tropical regions) and local (78 assemblages). Overall, more than three times as many species and twice as many genera were found in the tropics compared with the Arctic. The number of taxa restricted to a given zone (“climatic endemics”) was much higher in the tropics. All zonal and regional faunas had significantly fewer genera than expected (phylogenetic clumping), but this depletion was more substantial in the Arctic. Phylogenetically, younger families included fewer widely distributed genera and were more species rich at low latitudes, in conformity with the “Out of tropics” hypothesis. At the local level, there was no latitudinal difference in the average species richness. However, the Arctic assemblages comprised considerably fewer genera than expected, whereas phylogenetic diversity in the tropics only slightly deviated from the expected level. Thus, compared with the tropics, the Arctic harpacticoid fauna shows lower global but similar local species diversity and a lower level of endemicity. The Arctic fauna also shows stronger phylogenetic clumping at all scales, indicating multiple underlying processes of species filtering (evolutionary and ecological).

Replanting reduces frog diversity in oil palm

AbstractA growing body of literature has demonstrated significant biodiversity losses for many taxa when forest is converted to oil palm. However, no studies have directly investigated changes to biodiversity throughout the oil palm life cycle, in which oil palm matures for 25–30 yr before replanting. This process leads to major changes in the oil palm landscape that likely influence species assemblages and ecosystem function. We compare frog assemblages between mature (21–27‐yr old) and recently replanted (1–2‐yr old) oil palm in Sumatra, Indonesia. Across eighteen 2.25‐ha oil palm plots, we found 719 frogs from 14 species. Frog richness was 31 percent lower in replanted oil palm (nine species) than mature oil palm (13 species). Total frog abundance was 47 percent lower in replanted oil palm, and frog assemblage composition differed significantly between the two ages of oil palm. The majority of frog species were disturbance‐tolerant, although we encountered four forest‐associated frog species within mature oil palm despite a distance of 28 km between our study sites and the nearest extensive tract of forest. Although it is clear that protection of forest is of paramount importance for the conservation of tropical fauna, our results indicate that management decisions within tropical agricultural landscapes also have a profound impact on biodiversity. Practices such as staggered replanting or maintenance of connectivity among mature oil palm patches could help maintain frog diversity in the oil palm landscape.

Unravelling the role of allochthonous aquatic resources to food web structure in a tropical riparian forest.

The role of matter and energy flow across ecosystem boundaries for the subsidized consumer populations is well known. However, little is known on the effects of allochthonous subsidies on food web structure and trophic niche dimensions of consumers in the tropics. We excluded allochthonous aquatic insects from tropical streams using greenhouse-type exclosures to test the influence of aquatic allochthonous subsidies on the trophic structure and niche dimensions of terrestrial predators using stable isotope methods. In exclosure treatments, abundance and biomass of terrestrial predators, and biomass of phytophages decreased and increased, respectively. Vegetation-living predators were more responsive to allochthonous inputs than those living on the ground. Overall, lower availability of allochthonous inputs did not affect community-wide metrics and niche width of predators. However, the niche width of some spider families had very low overlap between treatments, and others had wider isotopic niches in the control than in the exclusion treatment. Most of the C and N in predators living in control stretches came from aquatic subsidies, and those predators living in the exclusion treatments switched their diets to terrestrial sources, showing a preference of predators for allochthonous subsidies. Our results suggest that allochthonous subsidies are also relevant to tropical fauna living upon vegetation. Moreover, allochthonous resources may amplify the niche dimension of certain predators or considerably change the trophic niche of others. Our study highlights the importance of including modern isotopic tools in elucidating the role of allochthonous resources on the patterns of trophic structure and niche dimensions of consumers from donor ecosystems.

The first mastotermitid termite from Africa (Isoptera: Mastotermitidae): a new species ofMastotermesfrom the early Miocene of Ethiopia

AbstractThe first mastotermitid termite from Africa is described and figured from wing fragments recovered from the early Miocene (22–21 Ma) deposits of the Mush Valley, Amhara Region, central Ethiopia.Mastotermes aethiopicusnew species is the second fossil termite recorded from Africa and expands the known paleo-distribution of the genus from tropical North America and Europe into northeastern Africa during the Miocene.Mastotermes aethiopicusis distinguished from the livingM.darwiniensisFroggatt and other Neogene species of the genus, and comments are provided regarding the occurrence of this genus in the tropical fauna of Miocene Ethiopia.

On the position of Uruguay in the South American biogeographical puzzle: insights from Ephemeroptera (Insecta)

AbstractAimTo study the relationships between Uruguay and neighbouring geographical areas based on distributions of Ephemeroptera species (mayflies: an ancient order of aquatic insects). We wanted to evaluate whether Uruguay more closely represents (1) the southern limit of the tropical (Paranense and Amazonian) fauna or (2) the northern limit of the temperate (Pampean‐Bonaerense) fauna.LocationSouth America with an emphasis on Uruguay.MethodsWe compiled more than 5000 collection records of mayfly species throughout South America and evaluated these using current taxonomy and geographical validity. We used the Network Analysis Method (NAM) on these data to identify units of co‐occurrence (UCs: mutually exclusive groups of co‐distributed species, with each group connected through strong links of sympatry and disconnected from the others). We focused solely on those UCs that included Uruguay in their spatial ranges and used these to infer the vicinity relationships.ResultsWe recovered four UCs consisting of many species that link Uruguay with tropical areas of Brazil and NE Argentina. These groups followed a geographically nested pattern. The results contradict the previously held view that the Uruguayan fauna holds strong affinities to that of temperate grasslands that lie to the south in central oriental Argentina (i.e. the currently accepted concept of Pampas). A comparison of the genera known from Uruguay and Buenos Aires Province further reinforces the distinction between Uruguay and temperate areas to the south.Main conclusionsThe hypothesis that Uruguay represents the southern limit of tropical affinities is strongly supported by mayfly distributions, indicating that a reappraisal of the Pampas as a cohesive biogeographical province is needed. We suggest that Uruguay and Buenos Aires should belong to different provinces, the former aligned with tropical provinces and the latter aligned with more temperate areas.

A New Eocene Casquehead Lizard (Reptilia, Corytophanidae) from North America.

A new fossil showing affinities with extant Laemanctus offers the first clear evidence for a casquehead lizard (Corytophanidae) from the Eocene of North America. Along with Geiseltaliellus from roughly coeval rocks in central Europe, the new find further documents the tropical fauna present during greenhouse conditions in the northern mid-latitudes approximately 50 million years ago (Ma). Modern Corytophanidae is a neotropical clade of iguanian lizards ranging from southern Mexico to northern South America.

Species composition and features of ichthyoplankton distribution in the waters of Senegal and Guinea-Bissau

The qualitative and quantitative composition of ichthyoplankton in the waters of Senegal and Guinea-Bissau during the winter period of 2012–2013 are considered. Approximately 120 species of pelagic eggs and larvae of fishes belonging to 64 families are identified in the ichthyoplankton samples. The eggs and larvae of Clupeidae, Carangidae, Scombridae, Myctophidae, Sparidae, Bothidae, Scianidae, and Paralepididae are dominant; the representatives of these families are present in ichthyoplankton over the entire water area under study. Among the commercial species, the eggs and larvae of sardinellas (round sardinella Sardinella aurita, Madeiran sardinella S. maderensis), West-African horse mackerel Trachurus trecae, jack mackerel Caranx rhonchus, and some other fishes of the tropical fauna are often recorded. The spawning biomass of principle commercial fish species is calculated based on the quantity of eggs laid by females.

A review of the MIS 5e highstand deposits from Santa Maria Island (Azores, NE Atlantic): palaeobiodiversity, palaeoecology and palaeobiogeography

The privileged location of Santa Maria Island (Azores archipelago) in the middle of the North Atlantic makes the fossiliferous outcrops on this island of utmost importance to gain a better understanding of how coeval living communities relate to the broader evolutionary and biogeographic history of the Atlantic basin during the late Neogene and the Quaternary. Here we focus on this island's MIS 5e fossil record, offering a comprehensive review on the palaeobiodiversity, palaeoecology and palaeobiogeography of the biota living in the mid North Atlantic during this interglacial. Several studies in oceanic islands stress the huge impact of sea level changes on insular communities. Pleistocene sea-level changes occur during the short-time events known as “Terminations” (associated to glacial/interglacial shifts) as well as with the onset of glaciations (associated to interglacial/glacial shifts). Both are responsible for extinctions and local disappearance of species, bottleneck effects and formation of new species, resulting in community structure changes. This work increases the number of fossil marine taxa reported from the Last Interglacial deposits of Santa Maria to 143 species. All the 19 new records are molluscs (13 gastropods and 6 bivalves), thus increasing the number of fossil molluscs to 136 species. Although thermophilic members of the “Senegalese” tropical fauna were found in these deposits, many of the most emblematic species (e.g., Persististrombus latus (=Strombus bubonius), Cymbula safiana, Harpa doris, Cardita senegalensis, Barbatia plicata, Ctena eburnea or Hyotissa hyotis) are absent, suggesting that they did not reach the Azores. Our results indicate that the main differences between the species composition of the MIS 5e and the present-day shallow-water Azorean communities are probably due to the dropping of sea surface temperature associated with the onset of the last glaciation, which had both direct and indirect effects on species ecology. A group of 21 thermophilic species was directly affected by the lower sea surface temperature, whereas a group of four sand-associated species was indirectly but similarly affected by the lowering of the sea level. Both groups have locally disappeared from the Azores. However, none of the extant endemic species found on the studied MIS 5e outcrops was apparently affected by the lowering SST. In contrast to the biogeographical relationships of the recent Azorean shallow marine molluscs, which are predominantly with the Mediterranean Region, Portugal and with the Madeira and Canary Islands archipelagos, the palaeobiogeographical relationships of the MIS 5e Azorean marine molluscs are mainly with Canaries and West Africa. Despite the general low similarity of the biogeographical relationships between the Azores and Cape Verde Archipelago, on both the recent and the MIS 5e analysis, this similarity is nevertheless higher for the MIS 5e mollusc assemblages, emphasizing the role of Cape Verde as an important source of warm-water species during the Last Interglacial.

Dynamics of abundance of eggs and larvae of common fish species in the central part of the Eastern Central Atlantic

Data on variation in the abundance of mass fish species at early stages of ontogenesis in different areas of the Eastern Central Atlantic in warm (June–November) and cold (December–May) seasons of 1994–2012 have been analyzed. The representatives of the mass species in the region are European pilchard Sardina pilchardus, common scad Trachurus trachurus, chub mackerel Scomber japonicus, round sardinella Sardinella aurita, Cunene horse mackerel T. trecae, and Atlantic bonito Sarda sarda. Within the economic zone of Morocco, variations in abundance of the representatives of the subtropical fauna (S. pilchardus, T. trachurus, and S. japonicus) at early stages of ontogenesis are similar over the entire area under study (32°–21°N). In the area of Mauritania (21°–16°N), variations in the abundance of the mass fish species of the tropical fauna (S. aurita, T. trecae, and S. sarda) at early stages of ontogenesis cannot be unambiguously compared with such variations in the area of Morocco because Senegal-Mauritanian populations of the species inhabit waters of different states and are not completely assessed by our surveys.

Descriptive and illustrated diagnosis of Ophiuroidea fauna (Echinodermata) in the shallow waters of North-eastern Brazil

In this study, we present descriptions, illustrations, comments, and bathymetric and geographic distributions of the brittle star species related to the estuary region of Camamu Bay, located in the State of Bahia, Brazil. The brittle star fauna lives on biological substrates, sand bottoms, mud and rubble in the Camamu Bay and comprises 12 species divided into five families. Almost all of them are common in the tropical and subtropical fauna of the regions of shallow water.Ophiophragmus filograneusis reported for the first time in Bahia, and nine other species are recorded for the first time in Camamu Bay:Amphipholis januarii, Amphipholis squamata, Ophiophragmus filograneus, Ophiostigma isocanthum,Ophioderma cinerea, Ophioderma januarii, Ophiactis lymani, Ophiactis savignyi andOphiocoma echinata.The results suggest that the ophiuroid assemblages are strongly affected by marine currents as well as by different kinds of bottom substrate.

The effects of changing climate on faunal depth distributions determine winners and losers.

Changing climate is predicted to impact all depths of the global oceans, yet projections of range shifts in marine faunal distributions in response to changing climate seldom evaluate potential shifts in depth distribution. Marine ectotherms' thermal tolerance is limited by their ability to maintain aerobic metabolism (oxygen- and capacity-limited tolerance), and is functionally associated with their hypoxia tolerance. Shallow-water (<200 m depth) marine invertebrates and fishes demonstrate limited tolerance of increasing hydrostatic pressure (pressure exerted by the overlying mass of water), and hyperbaric (increased pressure) tolerance is proposed to depend on the ability to maintain aerobic metabolism, too. Here, we report significant correlation between the hypoxia thresholds and the hyperbaric thresholds of taxonomic groups of shallow-water fauna, suggesting that pressure tolerance is indeed oxygen limited. Consequently, it appears that the combined effects of temperature, pressure and oxygen concentration constrain the fundamental ecological niches (FENs) of marine invertebrates and fishes. Including depth in a conceptual model of oxygen- and capacity-limited FENs' responses to ocean warming and deoxygenation confirms previous predictions made based solely on consideration of the latitudinal effects of ocean warming (e.g. Cheung et al., 2009), that polar taxa are most vulnerable to the effects of climate change, with Arctic fauna experiencing the greatest FEN contraction. In contrast, the inclusion of depth in the conceptual model reveals for the first time that temperate fauna as well as tropical fauna may experience substantial FEN expansion with ocean warming and deoxygenation, rather than FEN maintenance or contraction suggested by solely considering latitudinal range shifts.

Defining and dividing the greater Caribbean: insights from the biogeography of shorefishes.

The Greater Caribbean biogeographic region is the high-diversity heart of the Tropical West Atlantic, one of four global centers of tropical marine biodiversity. The traditional view of the Greater Caribbean is that it is limited to the Caribbean, West Indies, southwest Gulf of Mexico and tip of Florida, and that, due to its faunal homogeneity, lacks major provincial subdivisions. In this scenario the northern 2/3 of the Gulf of Mexico and southeastern USA represent a separate temperate, “Carolinian” biogeographic region. We completed a comprehensive re-assessment of the biogeography of the Greater Caribbean by comparing the distributions of 1,559 shorefish species within 45 sections of shelf waters of the Greater Caribbean and adjacent areas. This analysis shows that that the Greater Caribbean occupies a much larger area than usually thought, extending south to at least Guyana, and north to encompass the entire Carolinian area. Rather than being homogenous, the Greater Caribbean is divided into three major provinces, each with a distinctive, primarily tropical fauna: (1) a central, tropical province comprising the West Indies, Bermuda and Central America; (2) a southern, upwelling-affected province spanning the entire continental shelf of northern South America; and (iii) a northern, subtropical province that includes all of the Gulf of Mexico, Florida and southeastern USA. This three-province pattern holds for both reef- and soft bottom fishes, indicating a general response by demersal fishes to major variation in provincial shelf environments. Such environmental differences include latitudinal variation in sea temperature, availability of major habitats (coral reefs, soft bottom shorelines, and mangroves), and nutrient additions from upwelling areas and large rivers. The three-province arrangement of the Greater Caribbean broadly resembles and has a similar environmental basis to the provincial arrangement of its sister biogeographic region, the Tropical Eastern Pacific.

Rates of warming and the global sensitivity of shallow water marine invertebrates to elevated temperature

Assessing the sensitivity of ectotherms to variability in their environment is a key challenge, especially in the face of rapid warming of the Earth's surface. Comparing the upper temperature limits of species from different regions, at different rates of warming, has recently been developed as a method to estimate the long term sensitivity of shallow marine fauna. This paper presents the first preliminary data from four tropical Ascension Island, five temperate New Zealand and six Antarctic McMurdo Sound species. The slopes and intercepts of these three assemblages fitted within the overall pattern for previously measured assemblages from high temperature tolerance in tropical fauna and a shallow slope, to low temperature tolerance and a steep slope in Antarctic fauna. Despite the tropical oceanic Ascension Island being subject to upwelling events, the fit of the intercept and slope within the overall assemblage pattern suggests that the upwelling is sufficiently predictable for the fauna to have evolved the plasticity to respond. This contrasts with previously analysed species from the Peruvian upwelling region, which had a steeper slope than other temperate fauna. The speed and capacity of faunal assemblages to acclimatize their physiology is likely to determine the shape of the rates of warming relationship, and will be a key mechanism underpinning vulnerability to climate warming.

Odonata origins, biogeography, and diversification in an Eastern North American hotspot: multiple pathways to high temperate forest insect diversity

Abstract We assessed the origins and historical biogeography of a rich regional odonate fauna in New York State (NYS), Northeastern United States. We computed North American (NA) range centres and NYS range margins and reviewed the taxonomic literature to provide a useful phylogenetic framework for the fauna. We analysed results from a newly completed Odonata atlas using generalised linear anova models to assess the effects of species' origins and zoogeographic affinities on relative frequency and extinction risk metrics. Phylogenetic reconstruction based on taxonomic nomenclature revealed different patterns of diversification. Zygoptera in NYS is mainly of neotropical origin ˜ 60 Ma displaying a pattern of tropical conservatism, but with a burst recent of Plio–Pleistocene speciation in certain groups. Alternatively, Anisoptera contains crown group endemic taxa and other very old lineages from the Mesozoic era before the breakup of Pangaea, highlighting the evolutionary significance of the Appalachian Mountains as an important global centre of temperate forest freshwater diversity. These high regional levels of odonate diversity have been brought about by at least three different mechanisms: dependence on forests, predominance of non‐ecological speciation mechanisms, and niche conservatism across hundreds of millions of generations. NYS lies at a crossroads of both ancient and more recent Odonata evolution comprising separate boreal, temperate, and tropical faunas. Those species encountered less frequently and having higher overall extinction risk metrics generally tended to be the boreal species on the rear edge of their range, a widespread phenomenon for the insects of many regions generally attributed to ongoing climate change.

Aquatic biota of different karst habitats in epigean and subterranean systems of Central Brazil – visibility versus relevance of taxa

The karstic area of S&atilde;o Domingos, central Brazil, holds extensive drainage systems. In order to understand its biodiversity, various volumes of water were filtered with planktonic nets in stretches of subterranean and superficial rivers on five different occasions. We sampled four drips (152L), three calcite pools (368L), two subterranean rivers fed mainly by percolation water (6,395L), two subterranean rivers fed mainly by water coming from a sinkhole (4,175L) along different caves, one resurgence (158L), and four epigean rivers (101,690L). Physical and chemical variables were measured at some sites. Canonical Correlation Analysis was used to verify relationships between taxa and environment. The degree of similarity of the biota was assessed by cluster analysis (Sorensen, single linkage). There were records of exclusive taxa in epigean and subterranean samples, mainly in drips, which harbour the most unique fauna. The high richness of taxa presently recorded reveals the potential of the vadose zone biota in the tropical region, which was neglected in studies on Brazilian subterranean biodiversity. According to our results, the unsaturated zone tropical fauna may have different composition compared to that from temperate habitats. The studied communities were dominated by rotifers, while crustacean are predominant in the latter. The hypothesis can be clarified with the increase of long term studies and taxa identification at species level, besides the use of complementary sampling methods.

Pyrgeuma pyrgodesmoides, n. gen., n. sp., a new millipede from Malaysia with unusual surface structures (Diplopoda, Chordeumatida, Heterochordeumatidae)

Pyrgeuma pyrgodesmoides n. gen., n. sp., is described from the Cameron Highlands of Malaysia as the sixth (or possiblyseventh) species and third genus of the millipede family Heterochordeumatidae. The new species is remarkable in its re-semblance to members of the unrelated polydesmidan family Pyrgodesmidae, an interesting case of convergent evolutionin the tropical soil and litter fauna. The dorsal surface of the body is covered in small, curved, spatulate microtrichia and the metzonital setae are reduced to nearly undetectable size.