Reproductive features of the deep water hermit crab Sympagurus dimorphus (Anomura: Parapaguridae) inhabiting pseudoshells in the SW Atlantic Ocean

We herein provide information on reproductive aspects (the gonopore morphology of both sexes, the size of embryonic eggs and the fecundity) of the hermit crab Sympagurus dimorphus from deep waters of Argentina. Sampling was performed in different oceanographic and fishery campaigns between 2007 and 2010, at 38°01′–39°03′S, 55°–56°05′W, 85–150 m depth, in the SW Atlantic Ocean. Mean shield length (SL) of females was 9.41 ± 1.68 mm (range: 6.6–10.5 mm). Female gonopores measured 0.74 ± 0.10 mm (range: 0.45–0.90 mm), were oval in shape, and were more rounded and larger than male gonopores (0.51 ± 0.007, range: 0.4–0.63 mm). The egg volume for each of the three stages of embryonic development was 0.94 ± 0.20 mm³ for stage I, 1.14 ± 0.31 mm³ for stage II, and 2.07 ± 0.41 mm³ for stage III. Egg volume doubled from the initial to the final stage of the embryonic development. The fecundity (number of eggs) varied from 831 (6.62 mm SL) to 2246 (10 mm SL) for females carrying eggs in stages I+II, and between 158 (158 mm SL) and 1279 (9.4 mm SL) in stage III. The reproductive characteristics of the observed profile are intimately related to S. dimorphus use of a pseudoshell resource and a deep water habitat.     

The biology and functional morphology of the high-energy beach dwelling Paphies elongata (Bivalvia: Mactroidea: Mesodesmatidae). Convergence with the surf clams (Donax: Tellinoidea: Donacidae)

The biology and functional morphology of the Australian endemic Paphies elongata (shell length <20 mm) from wave-exposed beaches are described. On Middleton Bay Beach, Albany, Western Australia, the species co-occurs with the smaller (shell length <13 mm) Donax columbella. Both make tidally regulated migrations up and down the shore in the swash and backwash of waves, respectively. Emergence from and re-burrowing into the beach sand in concordance with the waves is fast in both taxa (5–10 s). Adaptations to such a life on these high-energy beaches include an anteriorly elongate and posteriorly reduced shell and a mesh of tentacles within the inhalant siphon that screens out sand grains from the mantle cavity but allows entry for particles of detritus that P. elongata suspension feeds on when they are raised into the water column with each breaking wave. Internally, relatively large ctenidia, small labial palps, a stomach with many sorting areas and a short intestine equip P. elongata for life in such a dynamic habitat. Strong rejectory currents in the mantle cavity keep it clean of sand. Paphies elongata is dioecious, as are species of Donax, which throughout its Australian range P. elongata is sympatric with. These donacid and mesodesmatid taxa have both evolved to exploit the niche and the food resource of detritus held in suspension by breaking waves of high-energy sandy beaches within their respective ranges. Of interest, however, is that the original and sole occupants of such beaches – the Mesozoic Upper Cretaceous Donacidae – have been joined subsequently by representatives of the Mesodesmatidae, such as P. elongata, the adoption of this habitat taking place in the Eocene of the Cenozoic, some 50 million years later.     

Breeding in the gray-headed tody-flycatcher (Aves: Tyrannidae) with comments on geographical variation in reproductive traits within the genus Todirostrum

The gray-headed tody-flycatcher Todirostrum poliocephalum is a passerine endemic to the Atlantic Forest of Brazil. We describe the nest and nesting behaviour of this species and investigate geographical variation in breeding traits in the genus using data from the literature, museum collections, and citizen science projects. We located 21 nests of the gray-headed tody-flycatcher, 13 of which we monitored. Nest height above the ground averaged 3.3 ± 3.4 m (n = 21). Nests were built over a 16.8 ± 5.6-day period (n = 6) by both adults. Clutch sizes ranged from two to three eggs, with a mean of 2.9 ± 0.3 eggs (n = 10). Eggs measured 16.6 ± 0.5 × 12.0 ± 0.5 mm (n = 23) and weighed 1.1 ± 0.1 g (n = 19). Mean incubation period was 17 days (n = 3) and mean nestling period was 15.5 days (n = 2). Apparent reproductive success was 30.8%, with predation being the primary cause of nest failure (46.1%). Mayfield’s reproductive success was 25.9%, and daily survival rates for eggs and nestlings were 0.957 and 0.971, respectively. Clutch sizes increased with latitude, but temperature and precipitation seasonality had very low importance in explaining clutch size variation.     

Allozyme comparison of the species and colour morphs of the nemertean genus Quasitetrastemma Chernyshev, 2004 (Hoplonemertea: Tetrastemmatidae) from the Sea of Japan

Biochemical genetics was applied to clarify the taxonomic status of the colour morphs of Quasitetrastemma nigrifrons and the sibling species Quasitetrastemma stimpsoni. Five colour morphs and two species were compared using 17 and 24 allozyme loci, respectively. The high average genetic identity value obtained for most of the colour morphs of Q. nigrifrons (I?=?0.981) suggests that they belong to the same species. Both Q. stimpsoni and Q. nigrifrons have a lower average I-value (I?=?0.718 ± 0.089) and are therefore considered to be separate species. According to the allozyme data, Q. nigrifrons var. pallidum is a heterogeneous group; most specimens are more similar to Q. nigrifrons, although some are closer to Q. stimpsoni.     

Larval anisakid nematodes from four species of squid (Cephalopoda: Teuthoidea) from the central and western North Pacific Ocean

Third-stage larvae of two species of the genus Anisakis, A. simplex (Rudolphi, 1809) and A. physeteris Baylis, 1923, and those of two types of Lappetascaris sp. are described from four species of squids from the central and western North Pacific Ocean. Larvae of Lappetascaris sp. Type A were 15-33 mm long and occurred individually free in the mantle musculature of squids, whereas those of Lappetascaris sp. Type B were considerably smaller, only 3–7 mm long, and were found in capsules on the stomach wall, each capsule containing up to 50–60 larvae. It is not known whether both larval types are conspecific or belong to two different Lappetascaris species. Anisakis simplex and A. physeteris larvae were found in Onychoteuthis borealijaponica Okada and Gonatopsis borealis Sasaki, and O. borealijaponica, respectively, whereas Lappetascaris sp. Type A and Type B larvae from Thysanoteuthis rhombus Troschel, Ommastrephes bartramii (LeSueur), Onychoteuthis borealijaponica and G. borealis, and O. bartramii, respectively. The findings represent several new host records and all these parasites are reported for the first time from squids in the central North Pacific Ocean.     

Bifurgaster,a new genus of Ascothoracida (Crustacea: Maxillopoda) parasitic in deep water asteroids

A new genus of ascothoracid, Bifurgaster gen. nov., has been found parasitizing brisingid asteroids Freyella spp. The genus comprises two species, B. freyellae sp. nov. and B. kermadeca sp. nov., from the north-east Atlantic Ocean and south Pacific Ocean respectively, at depths of over 4000 m. The genus is characterized by the adult female having a bilobed mantle within which is a reduced main body with little or no segmentation. The only appendages are the first antennae and second maxillae. Each lobe of the mantle contains two branches of the gut and ovary and a distinctive gland. Males and larvae of B. freyellae are described. The genus is placed in the family Dendrogastridae, and is thought to be intermediate between Ulophysema and Dendrogaster.     

Three new species of the genus Mononchus (Nematoda: Mononchida), and the “real” Mononchus truncatus Bastian, 1865

Mononchus altiplanicus sp. nov. from Chile is characterized by an average body length of 2.68 mm, dorsal tooth apex at about 30% of buccal capsule, transversal ribs anterior to tooth apex, tail on average eight anal body widths long. Mononchus oblongus sp. nov. from France is characterized by an average body length of 1.72 mm, shape and length of the buccal cavity (more elongate than in other congeners), relatively anterior position of the dorsal tooth apex, tail on average 8.2 anal body widths long, and seta-like subterminal caudal papillae. Mononchus medius sp. nov. from the USA is characterized by an average body length of 1.55 mm, posterior location of dorsal tooth apex, subventral ribs anterior to tooth apex, and tail on average 7.7 anal body widths long. Mononchus truncatus is rediagnosed on the basis of type/neotype specimens and those from Hungary. A key to species is provided.     

LX.—Copepoda and Cladocera of the Cuillin Hills of the Isle of Skye

Summary

The life history of the African grasshopper Ornithacris turbida (Walker) was studied under controlled laboratory conditions. No phase variation was observed between isolated and crowded stock in respect of colour, morphometrics, weight of hatchlings or fledglings. All the females reared in isolation Had seven nymphal instars but in the case of the isolated males the majority had six but some had seven nymphal instars. This variation was also observed in the crowded stock for both males and females.

In isolation the mean nymphal life of 15 females was 78·7 ± 3·2 days, the mean for nine males having six instars was 59·9 ± 3·2 days and for five males having seven instars the mean nymphal life was 74·6 ± 3·8 days. Overall the nymphal life for the insects reared in crowds was slightly shorter, but no attempt was made to separate the insects having six or seven instars.

The stripes in the compound eye correlated with the number of nymphal instars. Colour changes in the compound eye coincided with overall body colour changes and maturation.

The mean maturation period of females reared in isolation was 101 days, varying from 72 to 158 days. The mean maturation period of the crowded females, estimated by the collection of the first egg-pod, was 73 days with a range of 62 to 84 days; when estimated by the collection of egg-pods averaging one per female it varied with the cage from 91 to 114 days. This suggests that maturation in the crowded females was quicker.

The isolated females lived longer than ones reared in crowded conditions, and laid more egg-pods. There was, however, no difference in the number of eggs per pod or their hatchability between crowded and isolated stock. In both cases 76% of the total number of eggs hatched. Hence overall the isolated females had a greater fecundity than those reared in crowds.

The average weight of a single hopper from isolated parents was 15·5 mg and that from crowded parents was 14·0 mg.     

Life history of Paraselenis (Spaethiechoma) dichroa (Germar, 1824) (Coleoptera: Chrysomelidae: Cassidinae) in natural conditions of Atlantic Forest from Brazil

Cassidinae Gyllenhaal? is the second largest subfamily of Chrysomelidae (Coleoptera), which presents characteristic morphology, biology and behaviour. The current study describes the life cycle of Paraselenis(Spaetiechoma) dichroa (Germar), ?determining biological and behavioural aspects as well as the action of natural enemies on populations, when the species has maternal care. The study was conducted between February and April 2015 in the National Forest of Passa Quatro, municipality of Passa Quatro, Minas Gerais state, Brazil. Daily observations were made (morning and afternoon) to evaluate the offspring of females on Ipomoea sp. and Merremia macrocalyx (O’Donell?) (Convolvulaceae), as well as the actions of natural enemies on the young. The eggs are deposited on the midrib and abaxial surface of leaves (n = 25). Egg clusters are pedunculated, arranged in groups and devoid of any cover. On average, each female produced 27.3 ± 5.6 (n = 16) eggs, with a mean incubation period of 12.7 ± 2.9 days (n = 10 females with their young). The larvae remained grouped in the leaves throughout development, except when they fed. They retained faeces and exuviae as a stacked faecal structure on their mobile urogomphi (caudal process) like a faecal shield. The mean number of larvae per female was 12.7 ± 10.1 (n = 19) and the larval period lasted 24.9 ± 4.5 days (n = 12). Pupation occurred on the stem of the plant (n = 16). On average there were 8.1 ± 8.5 individuals for pupae progeny (n = 14). The mean duration of the pupal stage was 10.4 ± 3.3 days (n = 5). Overall, 3% of adults emerged (n = 13 individuals), with a total cycle time of 41.3 ± 8.4 days (n = 6). Adults are sexually dimorphic in the elytral shape. Females remain with the offspring throughout development. The natural enemies of immatures were Emersonella pubipennis Hansson? (Hymenoptera: Eulophidae), Tachinidae (Diptera) and Stiretrus decastigmus (Herrich-Schaeffer?) (Heteroptera: Pentatomidae), Conura sp. Spinola? (Hymenoptera: Chalcididae) and Brachymeria sp. Westwood? (Hymenoptera: Chalcididae). The information presented here on the natural history of P. dichroa are important as they may serve as a starting point to understand evolutionary questions and multispecies interactions.     

Female life‐history characteristics of the Mosor rock lizard,Dinarolacerta mosorensis (Kolombatović, 1886) from Montenegro (Squamata: Lacertidae)

Analysis of the female life history of the poorly studied endemic Balkan lizard species Dinarolacerta mosorensis was conducted on three population samples from Montenegro. One clutch is produced annually. Females mature at body sizes of 56–57 mm snout–vent length (SVL), attained at age 3–4 years. SVL increases with age. The average clutch size ranged from 4.3 to 5.2 eggs, and was significantly positively correlated with maternal SVL in two population samples. There were no trade‐offs between egg size/offspring size and clutch size, nor between variation in egg size/offspring size and maternal SVL. The incubation period averaged 26.5 days, while hatching success in captivity was 72%. Significant positive correlations were found between the hatchling mass and egg mass and size, and also between the hatchling total length and egg width and volume. There was a significant negative relationship between the hatchling mass and incubation duration.     

Breeding biology of the Pale-bellied Tyrant-manakin Neopelma pallescens (Aves: Pipridae) in south-eastern Brazil

The Pale-bellied Tyrant-manakin (Neopelma pallescens) inhabits semi-deciduous and riparian forests in central-north South America. Contrary to most manakins, there is no evident sexual dichromatism in the species and little is known about its breeding biology. We studied the breeding biology of a colour-banded population of the species from August to December 2016 and from August to October 2017 in the Campus Florestal of the Universidade Federal de Viçosa, south-eastern Brazil. The breeding season extended from early September to late November. The species is promiscuous, with males exhibiting simple courtship displays (exploded leks) in individual arenas. The nest (n = 13) is a cup attached by its top lip between forked branches and is very simple, with a structural layer made with dry grass stems and heads, attached to the branch with spider silk. The outer and lining layers are absent. The mean clutch size was 1.8 eggs (n = 11), which are oval and pale coloured, covered with spots of different shades of brown, often concentrated in the larger pole. Mean egg length and width (± SD) were 21.0 ± 0.9 × 15.8 ± 0.7 mm (n = 14) and the mean weight was 2.8 ± 0.4 g (n = 10). The incubation period could not be estimated, but the nestling period was 15 days (n = 2). The simple percentage of successful nests was 15.4%, with 76.9% of the nests depredated and 7.7% abandoned. This is the first detailed study about the breeding biology of any Neopelma species, providing relevant data for the study of the evolution of life history strategies not only for the genus, but for the whole family Pipridae.     

Diplecogaster tonstricula,a new species of cleaning clingfish (Teleostei: Gobiesocidae) from the Canary Islands and Senegal,eastern Atlantic Ocean,with a review of the Diplecogaster-ctenocrypta species-group

The Diplecogaster-ctenocrypta species-group is reviewed; it comprises two species. The clingfish Diplecogaster ctenocrypta from the Canary Islands is redescribed. The new species Diplecogaster tonstricula, a facultative cleaner of other teleosts, is described on the basis of eight specimens and colour photos from Senegal and the Canary Islands, eastern Atlantic Ocean. The species is small, apparently not exceeding 23 mm total length; it is characterised by having nine dorsal-fin rays, eight anal-fin rays, 24–25 pectoral-fin rays, 14–15 principal caudal-fin rays, 13–16 rakers on third gill arch, pelvic disc without lateral papillae in region A, disc region B with two rows of weak papillae, interorbital distance 4.1–4.6 in head length, distance between disc and anus 14–17% of SL, head and body with 10–13 narrow vertical brownish bars, cheek with a white ocellus surrounded by black, and with a small black spot in the middle. The new species is compared with other species of the genus; a key to the six known species of the eastern Atlantic, Mediterranean and Black Sea and South African genus Diplecogaster is presented. A checklist is provided for the species of Diplecogaster and their synonyms.     

Cladistic analysis of the pennatulacean genus Renilla Lamarck, 1816 (Coelenterata,Octocorallia)

The genus Renilla is an interesting taxon for phylogenetic studies, which includes six species endemic to America with an anphiamerican distribution Pacific-Atlantic Ocean). A cladistic analysis of Renilla Lamarck, 1816 using eight characters from external morphology produced one cladogram (length 14, CI = 0.92, RI = 0.87), and the characters were polarized using Echinoptilum macintoshii Hubrecht, 1885 as an outgroup. In the cladogram the following phylogenetic sequence results: ((R. koellikeri (R. muelleri, R. musaica)) (R. octodentata (R. reniformis, R. tentaculata))).     

I.—The prototheca of the Madreporaria,with special reference to the genera Calostylis,Linds., and Moseleya,Quelch

Summary

1. (1) The fecundity of Schilbe mystus (Linnaeus 1762) was determined by Stone's method through the examination of 53 ripe females.

2. (2) The fecundity of the specimens examined was found to vary in the range 7650-62118.

3. (3) In general fecundity is a function of length and weight of the specimen.

4. (4) The average diameter of the ova varied in the range 0.675–0.850 mm.

     

Rediscovery,natural history,and conservation status of Idiocranium russeli Parker, 1936 (Amphibia: Gymnophiona: Indotyphlidae)

The indotyphlid caecilian amphibian Idiocranium russeli Parker, 1936 is the only nominal species in its genus. Apart from two additional, largely overlooked locality records that we consider to be of an undescribed species, I. russeli is known with certainty from only a single collection of c.50 specimens from a single locality in 1933. We report new material from fieldwork in 2012 carried out in the vicinity of the type locality. Digging surveys at 34 sites for a total of >2000 person minutes found 50 I. russeli at 15 of these sites, extending the known range of the species by more than 40 km south and from an elevation of c.670 m to 104–820 m. The species probably occurs in nearby Nigeria and in some protected areas, is tolerant of some human disturbance, and is likely to move from Data Deficient to Least Concern on the IUCN Red List. Males have relatively longer and wider heads than females. Total length measured for preserved specimens is less than for freshly anaesthetized specimens, by up to 14.1%. Previously, preserved I. russeli were reported as having a maximum length of 114 mm, but the new sample includes specimens with total lengths of 145 mm in preservation and 167 mm when fresh. The sex of the smallest independent specimens (total length 62 mm in preservation) could be determined from examination of the gonads, hatchlings are c.30 mm, and I. russeli is confirmed as one of the smallest known caecilian species.     

An unusual ecology among whiptails: the case of Cnemidophorus lacertoides from a restinga habitat in southern Brazil

We studied the ecology of Cnemidophorus lacertoides at a restinga habitat in southern Brazil. Peak activity occurred between 12.00 and 15.00. The mean body temperature of active lizards (35.0 ± 2.9°C) was relatively low compared with other whiptails and was significantly influenced by environmental temperatures. Mean snout–vent length and mean body mass of individuals were 56.5 mm and 4.4 g, respectively. Male and female C. lacertoides were not significantly different in body size. Cnemidophorus lacertoides consumed 12 types of prey, with ants and spiders being the most important items. Unexpectedly, lizards did not consume termites, which tend to be very important items in the diets of most whiptails. We conclude that the population of Cnemidophorus lacertoides we studied deviates from the typical whiptail ecology because many of its ecological features differ from those of most other cnemidophorines of similar size.     

Studies on the life cycle of the cicadellid bug Empoasca dolichi Paoli,in Southern Nigeria

Summary

Studies carried out on the biology of E. dolichi Paoli showed that its eggs are palegreen to creamy white, elongate and often curved, and have a mean length and width of 0·84 mm and 0·16 mm respectively. The egg-incubation period averaged 8·3 days under uncontrolled insectary conditions of 21–32°C and 45–95% relative humidity, while the life-cycle from egg to adult averaged 17·5 days. In the insectary, mating in E. dolichi usually started between the third and sixth day after adult emergence. Over 56% of observed individuals mated on the 4th day. The observed diurnal mating period was mainly within 05·30–09·00 hours and 16·00–20·00 hours local time, with an average copulation period of 65·7 min. The mean pre-oviposition period of 3·0 days for 23 mated females was significantly shorter than 4·0 days for 21 unmated females. An average of 116 eggs and 96 eggs were laid by mated and unmated females respectively, but the fecundity rate (3 eggs/day of total life-span) of mated females was significantly higher than that (2 eggs/day) of unmated females. Unmated females lived longer (mean=49·7 days) than mated females with a mean of 38·3 days. The average life-span for mated and unmated males was 31·0 and 32·4 days respectively. Insectary and field observations revealed that females of E. dolichi preferentially lay their eggs into the stems, leaf-veins and leaf petioles of cowpea plants. Only mated females of E. dolichi laid viable eggs, and the observed male: female sex-ratio of their progeny in the insectary was 1:1·04.     

Schistosoma curassoni Brumpt, 1931 in sheep and goats in Senegal

A survey of 5722 sheep and 1752 goats at the abatoir in Dakar, Senegal showed that the overall prevalence of schistosomiasis was 2·1%. Of the 112 animals where identification of the schistosome species was possible, all were infected with Schistosoma curassoni, and 2·7% had mixed infections with S. bovis. The adult worms of S. curassoni are described, and on the basis of egg morphology this species is shown to be distinct from S. bovis and S. mattheei. Eggs of S. curassoni measured 146 μm ± 16·8 × 63·3 μm ± 4·5 from sheep and 149·4 μm ± 13·2 × 62·8 μm ± 4·9 from mouse liver, and appear to be indistinguishable from the eggs of S. haematobium Guede Chantier, Senegal which measure 153·1 μm ± 11·1 × 62·4 μm ± 12·1 from mouse liver. However, S. curassoni differs from S. haematobium in that it develops more quickly than S. haematobium in hamsters, uterine eggs becoming visible at least 20 days earlier; the adult worms of S. curassoni are nearly double the size of S. haematobium in hamsters at 70 days post infection.

Also, S. curassoni develops well in sheep and cattle unlike S. haematobium, but will not develop to maturity in baboons like S. haematobium.     

Morphology and composition of the internal axis in two morphologically contrasting deep-water sea pens (Cnidaria: Octocorallia)

Umbellula encrinus Linnaeus, 1758 and Anthoptilum grandiflorum (Verrill, 1879) are two species of deep-water sea pens (Cnidaria: Octocorallia) commonly found in the Northwest Atlantic. These sea pens are frequently caught as fishing bycatch, but little is known about their biology. Here we characterise the internal skeleton (axis) of these two morphologically contrasting species, in terms of axis carbonate composition and proportion, morphology and metrics (i.e. cross-sectional area and weight) through gradients along their lengths. Using the conspicuous growth rings present in the axis of U. encrinus we also estimated intra-colonial variation in radial growth rates for this species. X-ray diffraction (XRD) analyses revealed that the carbonate portion of the axis is composed of magnesian calcite (Ca, Mg)CO₃ in both species. On average, the axis is composed of 71% carbonate material in U. encrinus, and 65% carbonate in A. grandiflorum. The carbonate proportion was greatly reduced from base (71%) to tip (33%) in the axis of U. encrinus, while in A. grandiflorum changes were less abrupt (~6% difference from base to tip). In U. encrinus, the axis is quadrangular in shape through its whole length, twisting longitudinally. Twisting can occur in both clockwise and anti-clockwise directions. The axis of A. grandiflorum varied from elliptical near the base to cylindrical through most of the remaining length, with no twisting observed. Axes’ cross-sectional areas also decreased with distance from the base in both species, being the largest near the base. Estimated radial growth rates in U. encrinus were variable within a single colony, ranging between 0.04 and 0.08 mm.yr^?1. This is the first study to describe changes along the axes of sea pens, and to characterise the axes in the studied species. It provides a baseline for studies considering sea pens’ skeletons (e.g. ocean acidification and palaeoceanography).     

A new gigantic earthworm of the genus Metaphire Sims and Easton (Megascolecidae: Oligochaeta) from Taiwan with reference to evolutional trends in body sizes and segment numbers of the Pheretima genus-group

This paper describes a new species of gigantic terrestrial earthworm Metaphire taiwanensis sp. nov. from western Taiwan. It reached the maximum length of 860 mm for a living clitellate and 637 mm after preservation. It is an autochthonous species found in Mt Beidongyan and the Meifeng area of the Central Mountain Range at elevations of 1800–2100 m. M. taiwanensis is octothecate and protandric, characters shared by Metaphire stephensoni (Michaelsen) of Indochina, and Metaphire bununa Tsai, Tsai and Liaw and Metaphire paiwanna Tsai, Tsai and Liaw of Taiwan. These four species are combined as a new species-group called the stephensoni-group within the genus Metaphire Sims and Easton. It is closely related to the congeneric ignobilis species-group, which is also octothecate but holandric. It differs from holandric and quadrithecate Metaphire magna (Chen) of Hainan Island, in which the length also reaches 700 mm. Specific variation and evolutionary trends in sizes and segment numbers of the Pheretima genus-group are discussed.