Biometría de una población de Ammothella longipes (Hodge, 1864) (Pycnogonida)

Eleven parameters related to body size have been measured on 50 adult males and 50 adult females from a population of A. longipes collected in August on the red sea-weed Halopitys incuwus,from Oropesa (Castellón de la Plana, Spanish Mediten-anean). Two size-groups are clearly distinguished. Smaller individuals fonn 87-9 1°/0 of the population and are probably 10-11 months old, while larger ones are probably 16-17 months old. A moult between both age groups is likely. A linear growth model and a morphometric profile are proposed.Se han medido once parámetros referides a dimensiones corporales en 50 machos y 50 hembras adultos de una población de A. longipes recolectada en agosto en el alga roja Halopitys incurvus de Oropesa (Castellón de la Plana). Se reconocen claramente dos grupos de tamaño. Los individuos de menor tamaño representan el 87-91% de la poblacion y tendrían unos 10-11 meses de edad, mientras que los individuos de mayor tamaño tendnan unos 16-17 meses. Probablemente, hay una muda entre ambos grupos de edad. Se propone una curva de crecimiento linear y un perfil morfometrico de la especie

The genetic mating system of a sea spider with male-biased sexual size dimorphism: evidence for paternity skew despite random mating success

Male-biased size dimorphism is usually expected to evolve in taxa with intense male–male competition for mates, and it is hence associated with high variances in male mating success. Most species of pycnogonid sea spiders exhibit female-biased size dimorphism, and are notable among arthropods for having exclusive male parental care of embryos. Relatively little, however, is known about their natural history, breeding ecology, and mating systems. Here we first show that Ammothella biunguiculata, a small intertidal sea spider, exhibits male-biased size dimorphism. Moreover, we combine genetic parentage analysis with quantitative measures of sexual selection to show that male body size does not appear to be under directional selection. Simulations of random mating revealed that mate acquisition in this species is largely driven by chance factors, although actual paternity success is likely non-randomly distributed. Finally, the opportunity for sexual selection (Is), an indirect metric for the potential strength of sexual selection, in A. biunguiculata males was less than half of that estimated in a sea spider with female-biased size dimorphism, suggesting the direction of size dimorphism may not be a reliable predictor of the intensity of sexual selection in this group. We highlight the suitability of pycnogonids as model systems for addressing questions relating parental investment and sexual selection, as well as the current lack of basic information on their natural history and breeding ecology

Taxonomy and distribution of Italian and Antarctic Pycnogonida, with identification keys to genera and species

openQuesta tesi fornisce una descrizione dei progetti realizzati nel triennio 2018-2021 nell'ambito dello studio dei Picnogonidi. Viene riportata una panoramica generale della classe Pycnogonida (Arthropoda, Chelicerata), evidenziando le principali caratteristiche di questi organismi. Successivamente viene proposta la checklist aggiornata dei Picnogonidi italiani (Colasanto e Galli, 2021) con la distribuzione dettagliata delle specie, generata undici anni dopo quella di Bartolino e Chimenz (2010). La chiave dicotomica proposta per l'identificazione delle specie fa riferimento a questi documenti. La chiave è stata ottenuta attraverso indagini bibliografiche sulle caratteristiche morfologiche della specie, integrando con informazioni tratte da chiavi già presenti in letteratura (in particolare, Munilla e Soler-Membrives, 2014) e analisi di campioni in laboratorio. Parallelamente allo studio dei Picnogonidi italiani, sono stati esaminati gli esemplari conservati al Museo Nazionale dell'Antartide ed è stato effettuato uno studio di DNA barcoding su alcuni di essi. Sono state abbozzate chiavi di identificazione di generi e specie, sulla base delle caratteristiche morfologiche. Conseguentemente, viene riportata anche la checklist aggiornata dei Picnogonidi antartici e sub-antartici. Si riportano infine alcune considerazioni sulla possibilità di coinvolgere i subacquei nel monitoraggio dei Picnogonidi attraverso progetti di citizen science.This thesis provides a description of the projects carried out in the three-year period 2018-2021 as part of the study of Pycnogonida. A general overview of the class Pycnogonida (Arthropoda, Chelicerata) is reported, highlighting the main characteristics of these organisms. Subsequently, the updated checklist of the Italian pycnogonids (Colasanto and Galli, 2021) is proposed with the detailed distribution of the species, generated eleven years after that of Bartolino and Chimenz (2010). The dichotomous key proposed for the species identification refers to these documents. The key was obtained through bibliographic investigations on the morphological characteristics of the species, integrating with information taken from keys already present in the literature (in particular, Munilla and Soler-Membrives, 2014) and laboratory analysis of samples. Parallel to the study of the Italian pycnogonids, specimens preserved at the National Museum of Antarctica were examined and the barcoding DNA of some of them was sequenced. Identification keys to genera and species were sketched, based on morphological characters. Therefore, the updated checklist of Antarctic and sub-Antarctic Pycnogonida is also reported. Finally, some considerations on the possibility to involve Scuba-divers on pycnogonids monitoring through citizen science projects are reported.openXXXIV CICLO - SCIENZE E TECNOLOGIE PER L'AMBIENTE E IL TERRITORIO (STAT) - Scienze del mareColasanto, Elis

Premiers pycnogonides cótiers du détroit de Gibraltar (coté ibérique)

Ha estat estudiada una col•lecció de 107 picnogònides costaners, recollits entre la superfície i els 12 m de fondària (nivells mediolitoral i infralitoral) sobre substrats diversos, que ban proporcionat 11 espècies pertanyents a 7 gèneres i 5 famílies. Les espècies més abundants són Achelia echinata, Ammothella longipes i Callipalene emaciata. Hom comenta llur distribució europea. Aquesta fauna sembla totalment mediterrània.A faunistic study of 107 coastal Pycnogonida, sampled to 12 meters deep, is realized on various substrates in the medio-littoral and infralittoral zones. Eleven species have been detected, belonging to 5 families and 7 genera. Achelia echinata, Ammothella longipes and Callipalene emaciata are the most frequent taxa. Their European distribution is presented. This fauna is similar to the Mediterranean one

Checklist of the Invertebrate Animals Reported from the Region of Port Aransas, Texas

This checklist is of preliminary form with the hope that this will be a beginning for a more complete annotated list of the fauna and flora of this region. In many cases this list is quite obviously incomplete, however further work on the taxonomy of the biota of this region will gradually fill the incomplete gaps, and the resulting list should then prove quite useful to field investigators in this area.Marine Scienc

한국산 바다거미류의 분류학적 연구

학위논문 (박사) -- 서울대학교 대학원 : 자연과학대학 생명과학부, 2020. 8. 김원.Systematic studies on the Sea Spiders (Arthropoda: Chelicerata: Pycnogonida) from the Korean waters were conducted. Various sampling methods were used, including, SCUBA, grab, and light trap. A total of 43 species (1,321 individuals) were obtained. A systematic review of Korean pycnogonids was completed based on observed morphological and molecular characteristics. The following conclusions were obtained by reviewing the Korean pycnogonid, based on newly obtained specimens in Korean waters, type specimens, and each species original description. 1. Five species [Cilunculus armatus (Böhm, 1879), Decachela discata Hilton, 1939, Hedgpethia chitinosa (Hilton, 1943), Pallenopsis temperans Stock, 1953, Pycnogonum (Pycnogonum) tenue Slater, 1879] collected in the Korean Strait were included as Korean pycnogonids. Four species, except C. armatus, were excluded from the Korean pycnogonids since the collection coordinates of these four species are confirmed to be outside the Korean water boundaries according to the Korea-Japan continental shelf boundary treaty. 2. Achelia latifrons (Cole, 1904) was newly reported in Korean waters in 1954. Since it was a juvenile specimen, its identification was uncertain. Moreover, Achelia orpax Nakamura & Child, 1983, the most similar species to A. latifrons, was reported as a new species. Research was needed to distinguish A. latifrons from its congener, A. orpax and it was necessary to ensure identification from the juvenile specimen. Based on morphological and molecular analysis, the author confirms that its identification is correct. 3. There were errors in the morphology descriptions and classifications of 8 species [Ammothea hedgpethi (Utinomi, 1959), A. hilgendorfi (Böhm, 1879), Paranymphon magnidigitum Hong & Kim, 1987, Callipallene amaxana, (Ohshima, 1933), C. sagamiensis Nakamura & Child, 1983, Endeis nodosa Hilton, 1942, Anoplodactylus crassus Nakamura & Child, 1988, A. erectus Cole, 1904, A. velamellus Nakamura & Child, 1991] in Korean pycnogonids. Based on the examined material and the original descriptions, the morphological characteristics were reviewed to correct any error in the previous literature. In addition, newly discovered classification methods were applied to these species. 4. Additional variations of 13 species species [Achelia alaskensis (Cole, 1904), A. orpax Nakamura & Child, 1983, Ammothella indica Stock, 1954, Paranymphon spinosum Caullery, 1896, Tanystylum scrutator Stock, 1954, T. ulreungum Kim, 1983, Ascorhynchus glaberrimus Schimkewitsch, 1913, A. ramipes (Böhm, 1879), Nymphonella tapetis Ohshima, 1927, Nymphon japonicum Ortmann, 1891, N. kodanii Hedgpeth, 1949, N. longitarse Krøyer, 1844, N. striatum Losina-Losinsky, 1929] were recorded. 5. Achelia ohshimai Utinomi, 1951 was reported as a new species in Japan that was synonymized with A. bituberculata Hedgpeth, 1949. Based on comparison of mtCOI DNA barcode, A. ohshimai has been returned to species level instead of a synonym of A. bituberculata. Six previously unrecorded in Korean pycnogonids were found during field surveys, and described in detail. 1. A candidate of new species was found in Jejudo Island and identified to Pycnogonum (Nulloviger) sp. nov. 2. Five species [Achelia spatula Nakamura & Child, 1983, Pallenopsis sibogae Loman, 1911, Anoplodactylus stellatus Nakamura & Child, 1983, A. tubiferus (Haswell, 1884), Pycnogonum (Pycnogonum) tenue Slater, 1879] are newly discovered in Korean waters. Among them, A. spatula and A. stellatus are only the second specimens to be collected since the holotype was first reported, and a female specimen of A. stellatus was newly discovered in the present study. In addition, Cilunculus armatus was collected in Korean waters. It is the first time that actual specimens have been observed, so its morphology is described in detail. Previous studies on Korean pycnogonids have been conducted based on morphology. In this study, a total of 36 mtCOI DNA barcodes from 36 species were analyzed. The morphological characteristics of each specimen were also analyzed, and intra- and interspecific variations were presented for the first time.한국 해역에 서식하는 협각아문 바다거미강에 대한 분류학적 연구를 수행하였다. 스쿠버다이빙, 그랩, 라이트 트랩 등 다양한 채집 방법으로 국내·외에 서식하는 43종 1,321개체의 바다거미류 표본을 확보하였고, 형태학적 형질과 분자생물학적 형질을 바탕으로 한국산 바다거미류에 대해 분류학적 재검토를 시행하였다. 한국 해역에서 새롭게 채집된 표본과 재검토 대상 분류군의 모식표본, 원기재 문헌을 중심으로 한국산 바다거미류를 재검토하여 다음과 같은 결론을 얻었다. 1. 대한해협에서 발견된 5종[Cilunculus armatus (Böhm, 1879), Decachela discata Hilton, 1939, Hedgpethia chitinosa (Hilton, 1943), Pallenopsis temperans Stock, 1953, Pycnogonum (Pycnogonum) tenue Slater, 1879]이 한국산 바다거미류로 보고되었으나, C. armatus를 제외한 나머지 4종의 채집기록은 한·일 대륙붕 경계선 조약에 근거한 한국 해역의 경계선 밖에서 확인되기 때문에 한국산 바다거미류에서 제외함. 2. Achelia latifrons (Cole, 1904)는 1954년에 한국산 바다거미류로 확인되었지만 유생 단계 표본만 확보되었고, 형태가 유사한 Achelia orpax Nakamura & Child, 1983이 뒤에 신종으로 보고되었기 때문에 동정이 모호했음. 해당 표본을 대여하여 관찰하고 성체와 유생 단계 표본의 형태적 형질과 분자생물학적 형질을 함께 비교하여 기존의 동정을 확증하였음. 3. 기존 한국산 바다거미류의 형태 기재 및 분류 방법에 오류가 있었던 8종[Ammothea hedgpethi (Utinomi, 1959), A. hilgendorfi (Böhm, 1879), Paranymphon magnidigitum Hong & Kim, 1987, Callipallene amaxana, (Ohshima, 1933), C. sagamiensis Nakamura & Child, 1983, Endeis nodosa Hilton, 1942, Anoplodactylus crassus Nakamura & Child, 1988, A. erectus Cole, 1904, A. velamellus Nakamura & Child, 1991]의 형태적 형질을, 확보된 표본 및 원기재 문헌을 중심으로 재검토하여 기재 오류를 수정하고 새롭게 발견된 분류 방법을 적용함. 4. 13종[Achelia alaskensis (Cole, 1904), A. orpax Nakamura & Child, 1983, Ammothella indica Stock, 1954, Paranymphon spinosum Caullery, 1896, Tanystylum scrutator Stock, 1954, T. ulreungum Kim, 1983, Ascorhynchus glaberrimus Schimkewitsch, 1913, A. ramipes (Böhm, 1879), Nymphonella tapetis Ohshima, 1927, Nymphon japonicum Ortmann, 1891, N. kodanii Hedgpeth, 1949, N. longitarse Krøyer, 1844, N. striatum Losina-Losinsky, 1929]에 대해 새롭게 발견된 형태변이를 추가 기록함. 5. 일본에서 신종으로 보고되었된 Achelia ohshimai Utinomi, 1951은 Achelia bituberculata Hedgpeth, 1949의 synonym으로 여겨졌으나 한국 해역에서 채집된 표본의 DNA 바코드 분석을 통해 A. bituberculata 와는 별개의 종임을 확인하고 A. ohshimai를 적합명칭으로 되돌림. 본 연구를 위한 표본확보 중 6종의 미발굴 바다거미류 표본을 확보하여 다음과 같이 동정하고 기재하였다. 1. 제주해역에서 한 종의 송장바다거미류 신종후보종 표본이 채집되어 Pycnogonum (Nulloviger) sp. nov. 로 기재하였음. 2. 제주와 남해, 동해해역에서 미기록종 5종[Achelia spatula Nakamura & Child, 1983, Pallenopsis sibogae Loman, 1911, Anoplodactylus stellatus Nakamura & Child, 1983, A. tubiferus (Haswell, 1884), Pycnogonum (Pycnogonum) tenue Slater, 1879]이 발견되어 기재하였으며, 이중 A. spatula와 A. stellatus는 원기재 이후 두 번째로 발견된 표본이며 A. stellatus 암컷 표본이 최초로 발견되어 암수 형태 차이를 기재함. 또한 한국산 기록으로 인정되었으나 국내에 표본이 존재하지 않아 형태관찰이 불가능했던 C. armatus 표본이 남해해역에서 확보되어 형태를 자세히 관찰하고 형태변이 포함하여 재기재하였다. 기존의 한국산 바다거미류의 분류학적 연구는 형태 분석에 기반한 연구가 수행되었으나 본 연구에서는 형태 분석을 통한 연구와 함께 총 36종의 한국산 바다거미류의 mtCOI DNA 염기서열을 분석하였으며 한국산 바다거미류의 종내변이율과 종간변이율을 비교하여 처음으로 제시하였다.INTROUCTION . 1 1. Background 2. General morphology of Class Pycnogonida MATERIAL AND METHODS . 11 1. Sampling 2. Material treatments 3. Measurements 4. Molecular experiments RESULTS 19 1. Morphological analysis 1.1. Species found in Korean strait 1.2. List of Pycnogonida species in Korean waters 1.3. Systematic accounts 2. Molecular analysis CONCLUSION . 242 REFERENCES . 252 ABSTRACT (IN KOREAN) 272Docto

Picnogónidos litorales recogidos sobre el alga Mesophyllum lichenoides en Nerja (Málaga, Mar de Alborán)

A collection of 133 specimens, captured in 1983 at 3 - 4 m depth, include 10 species: Ammothella longipes, A . uniunguiculata, Achelia echinata, A.langi, Tanystylum conirostre, Anoplodactylus pygmaeus, Callipallene emaciata, C. producta, C. tiberi and Pycnogonum pussillum. The latter is the second record for the iberian coast. Likewise, C. tiberi is the first record in the Spanish mediterranean sea and the second one from the iberian coasts. A . langi and T. conirostre are the more abundant species in this substrate. Data about abundance (percentage and number of pycnogonids for 100 g of seaweed dry weight) are reported. This collection is typical of the Mediterranean sea. At present, 32 species are recorded in the south of SpainSe han capturado durante el a80 1983, 133 picnogonidos entre 3 y 4 m de profundidad en una playa de Nerja (Málaga, Mar de Alborán). Entre las 10 especies recolectadas (Ammorhella longipes, A.uniunguiculata, Achelia echinata, A.langi, Tanystylum conirostre, Anoplo-dactylus pygmaeus, Callipallene emaciata, C.producta, C.tiberi y Pycnogonum pusillum), la penúltima es primera cita en el Mediterraneo español y segunda para las costas ibéricas y P.pusillum constituye la segunda cita en el litoral ibérico. Las especies más abundantes son A.langi y T.conirostre. Se aportan abundancias específicas en porcentajes y en número de individuos referidos a 100 g de peso seco algal. La presente colección es típica de la zona mediterranea. Hasta ahora, se han citado 32 especies en el sur de España