Manuel Malaquias

Manuel Malaquias
University of Bergen | UiB · Department of Natural History, University Museum

PhD

About

138
Publications
80,681
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
2,040
Citations
Introduction
My research is focused on the study of the patterns and causes that drive present diversity in the oceans. Cephalaspidean gastropods, a group of poorly known marine snails, are my favorite model animals and I use morphological and DNA characters to recognize species and reconstruct hypotheses of evolution and relationships (phylogenies) at species, genera, and family level.
Additional affiliations
September 2002 - January 2007
Natural History Museum, London
Position
  • PhD Candidate / Postdoctoral fellow
October 2008 - present
University of Bergen
Position
  • Professor (Full)
Description
  • How do species originate in the oceans? And what causes their extinction? Why some regions in the oceans are more diverse than others? Are the mechanisms responsible for the patterns of diversity in the deep-sea the same as in shallow ecosystems? Understanding the patterns and causes that drive present diversity in the oceans it’s one of the main goals of my research. As model organisms I use a group of gastropod molluscs – the cephalaspids. The study of the diversity, systematics and evolution

Publications

Publications (138)
Article
Nudibranch molluscs Coryphella are widely distributed and species-rich gastropod group lacking fossil record and displaying a complex distribution across both Southern and Northern hemispheres. In this paper we provide a detailed review of the morphology, ecology, and distribution of Coryphella, estimation of divergence times between species, an an...
Article
Species of the genus Eubranchus Forbes, 1838 (Mollusca: Gastropoda: Nudibranchia) are common faunistic elements of boreal benthic ecosystems, associated with hydroid communities. Recent studies have suggested that the widely distributed trans-Arctic E. rupium (Møller, 1842) constitutes a complex of at least three candidate species, but the detailed...
Book
Full-text available
Sea slugs mesmerize with their unparalleled beauty, boasting extravagant colours and unique body shapes. Their magnificence draws the attention of divers and underwater photographers from across the globe, who eagerly seek out and document these remarkable creatures. Beyond their aesthetic appeal, sea slugs exhibit remarkable biology and evolutiona...
Article
Full-text available
Scaphander is a genus of mostly deep-sea, soft-bottom gastropods distributed nearly worldwide. Its taxonomic history is complex, with 32 species currently accepted, most based on shells only. In this work, we revise the diversity and systematics of Scaphander, with a focus on the Indo-Pacific region, using a detailed morphological study and molecul...
Chapter
Muscular systems of euopisthobranchs comprise body muscles and the muscular tissue of internal organs. Body wall musculature is stronger in species without a shell or with a reduced shell. Most euopisthobranchs have a muscular ventral foot for benthic locomotion. However, in pteropods, the foot is highly modified into wing‐like parapodia used for s...
Chapter
The integument comprises the epidermis formed by a layer of cells with apical microvilli and cilia, underlined by connective tissue with some muscle fibers, nerves, and different types of glands. Mucus is the main secretory product of the integument, but glands that release bioactive compounds are crucial for the chemical defense strategies of thes...
Article
Full-text available
In this paper we review the Heterobranchia (excluding Pyramidelloidea) of the Lower Piacenzian, Upper Pliocene of Estepona, southern Spain. 59 species are reviewed representing 37 genera. Voluta exilis Eichwald, 1829 is a junior homonym of Voluta exilis Gmelin, 1791, therefore Ringicula guzhovi nov. nom. is proposed for the Paratethyan species. Tor...
Chapter
Full-text available
In euopisthobranchs, the shell can be external, covering the whole body or just part of it, but in many species, the shell is internal and greatly reduced or completely absent. External shells are morphologically diverse, being limpet‐like in umbraculids, bubble‐shaped in several cephalaspideans, coiled, globular, triangular, or needle‐shaped in Eu...
Chapter
Full-text available
As in other gastropods, in euopisthobranchs the pericardial cavity that surrounds the heart is spatially and functionally connected to the excretory system, forming the renopericardial system. Podocytes or podocyte‐like cells of the auricular epicardium and pericardium wall mediate selective fluid transfer from the circulatory system into the peric...
Chapter
Full-text available
In euopisthobranchs, the circulatory system can be described as semi‐open. Propelled by the heart, hemolymph runs via aortas and arteries into larger or smaller anastomosing sinuses that are often subsumed under the term hemocoel. Collecting sinuses transport the hemolymph via gill and kidney veins into the heart. The heart consists of an auricle a...
Chapter
Full-text available
The euopisthobranchs constitute a taxon of marine gastropods with around 1000 described species. This taxon has a worldwide distribution, from tropical to polar seas, ranging in habitats from intertidal to the deep marine ecosystems. The euopisthobranchs present a large morphological diversity. In some species the shell is external, but there is a...
Chapter
Full-text available
Like in other mollusks, Euopisthobranchia possesses two different mesodermal body cavities that are discriminated by their lining. The pericardium is a secondary or coelomic body cavity, lined by an endothelium consisting of epithelio‐muscle cells, podocytes, and lining cells. The pericardium surrounds the heart that consists of a single auricle an...
Chapter
Full-text available
In most euopisthobranchs, the buccal cavity contains the radula. A pair of salivary glands releases into the buccal cavity a fluid for agglutination and lubrication of the food during feeding and ingestion. The esophagus can include a crop to accommodate ingested food, and many euopisthobranchs possess a gizzard with hard plates for food grinding....
Chapter
Full-text available
In euopisthobranchs, the gill is external on the right side of the animal or is located within the mantle cavity. The term plicatidium designates the gills of euopisthobranchs which have a highly folded structure, being distinct from the lamellar ctenidial gills of other mollusks. In Aplysia , the gill is formed by wedge‐shaped pinnules in which th...
Article
Onchidoris muricata (Gastropoda: Nudibranchia: Onchidorididae) is a well-known nudibranch species, which has a wide amphiboreal range confirmed by molecular data. However, O. muricata shows a high degree of variation in external morphology among distant populations, which may indicate the presence of cryptic diversity within this species. There are...
Article
Full-text available
Haminoea are herbivorous, coastal snails occurring in temperate and tropical waters of the Atlantic and Eastern Pacific oceans, with one species present in temperate South Africa (Indian Ocean). The genus is taxonomically difficult as several available nominal species were introduced based on shell descriptions alone, or described based on subtle d...
Article
Full-text available
Trait-based approaches that complement taxonomy-based studies have increased in popularity among the scientific community over the last decades. The collection of biological and ecological characteristics of species (i.e., traits) provides insight into species and ecosystem vulnerability to environmental and anthropogenic changes, as well as ecosys...
Article
Full-text available
Color ontogeny and variations associated with discrete morphological differences may generate taxonomical challenges, which requires multiple data types and in-depth historical review. The nudibranch known as the Spanish dancer, Hexabranchus sanguineus , is a classic example with over 200 years of taxonomic confusion. Currently, H. sanguineus is ac...
Article
The study of newly collected, live specimens of Pupa (Acteonidae) from New Caledonia and French Polynesia, revealed the presence of six distinct species in this region, including an undescribed species. All these species are re-described and/or named using molecular and morphological evidence as well as a review of the literature and examination of...
Article
Owing to the small size and cryptic morphology, runcinids are among the most difficult marine heterobranchs to study and consequently one of the groups about which little is known. Only recently were molecular tools and phylogenetics first employed to study the systematics. The charismatic European reddish-brown species Runcina ferruginea Kress, 19...
Article
Full-text available
The systematics of the marine mollusc family Velutinidae has long been neglected by taxonomists, mainly because their often internal and fragile shells offer no morphological characters. Velutinids are usually undersampled owing to their cryptic mantle coloration on the solitary, social or colonial ascidians on which they feed and lay eggs. In this...
Article
The genus Haloa includes dull-coloured species of haminoeid snails inhabiting tidal and shallow waters of the tropical and sub-tropical Indo-West Pacific. This paper reports on the diversity and systematics of Haloa based on the phylogenetic hypothesis generated by Oskars and Malaquias (2019) and on the morphological study of specimens. Shells, ext...
Article
Full-text available
In this letter we highlight the inconsistencies and dismantle the arguments used by Korshunova et al . (2021) where the authors have treated the nudibranch species Polycera norvegica as a junior synonym of Polycera capitata (original designation: Thecacera capitata ). We show that in accordance with the International Code of Zoological Nomenclature...
Article
Conformity of trans-Arctic Coryphellidae genera with the most recent revised taxonomy for the group was tested. Both morphological and molecular data were used to compare more than 200 specimens from various localities in the North Pacific, North Atlantic and Arctic Oceans. The molecular study included four markers (COI, 16S, H3 and 28S) and implem...
Article
We present the most comprehensive phylogeny of a globally distributed deep-sea group of gastropods published to date including over 80% of the recognized diversity of the family Scaphandridae. The definition and taxonomic composition of the Scaphandridae has been hampered by the lack of a sound phylogenetic framework and definition of synapomorphic...
Article
Full-text available
Scaphander gracilis Watson, 1883 is a deep-sea Cephalaspidea gastropod species endemic to the Azores in the mid-North Atlantic, and which was up to now only known from empty shells with a unique thick callus. Here, we describe for the first time the morphology of this snail species from anatomical dissections and provide a DNA barcode. A phylogeny...
Article
Full-text available
Background Heterobranchia is a diverse clade of marine, freshwater, and terrestrial gastropod molluscs. It includes such disparate taxa as nudibranchs, sea hares, bubble snails, pulmonate land snails and slugs, and a number of (mostly small-bodied) poorly known snails and slugs collectively referred to as the “lower heterobranchs”. Evolutionary rel...
Article
Full-text available
To investigate the conspecificity of different morphotypes of Jorunna tomentosa (Cuvier, 1804) (type species of genus Jorunna Bergh, 1876), we studied specimens sampled from across part of the geographical distribution of the species, using a combination of morphoanatomical characters and molecular phylogenetics. Bayesian and maximum likelihood phy...
Article
Full-text available
Nakamigawaia is a poorly understood genus of Aglajidae sea slugs with only two species formally ascribed. In this paper we explore new morpho-anatomical characters using stereo and scanning electron microscopy and employ different molecular approaches (a cytochrome c oxidase sub-unit I gene phylogeny, the Automatic Barcode Gap Discovery species del...
Article
Full-text available
The genus Thuridilla Bergh, 1872 comprises mostly tropical sap‐sucking sea slugs species with flamboyantly coloured forms. However, the potential for cryptic or pseudocryptic species masked by convergent or polymorphic colour patterns has not been tested using molecular characters. In this study, we sampled 20 of the 23 recognized worldwide species...
Article
Full-text available
The genus Micromelo (family Aplustridae) occurs in almost all tropical and subtropical waters across the globe, with the exception of the Eastern Pacific. Most authors consider Micromelo undatus (Bruguière, 1792) as the only valid species in this genus. This study examines populations of specimens identified as M. undatus across its geographic rang...
Article
Full-text available
Runcinida is a small heterobranch order of sea slugs with 61 known species distributed worldwide across temperate and tropical latitudes with two established families (Ilbiidae and Runcinidae). Little is known about the phylogenetic relationships within Runcinida. Here, we present the first molecular phylogeny of the order with an emphasis on Europ...
Article
Full-text available
The genus Papawera includes two species of haminoeid snails found only in temperate waters of New Zealand and southeastern Australia. In this work, we redescribe the Papawera species based on characters of their external morphology, shells, and anatomical features such as radulae, jaws, gizzard plates, and male reproductive systems, using for the f...
Article
Full-text available
The genus Lamprohaminoea includes species of colourful haminoeid snails associated with coral reefs and rocky shores in the tropical Indo-West Pacific. In this work, we revise the diversity and systematics of Lamprohaminoea species based on a phylogenetic hypothesis and on a detailed morphological analysis of specimens. Shells, external features of...
Article
In this work we report on a mating aggregation of the marine mangrove dweller gastropod Bakawan rotundata (A. Adams, 1850), observed in the Sewri mud flats near Mumbai in western India. From October 2018 the area has been surveyed monthly for its biodiversity composition. In April 2019, large amounts of snails were observed and their abundance was...
Article
Full-text available
This work aimed to test whether the colour variability featured by the European nudibranch Polycera quadrilineata is consistent with the concept of a single polychromatic species or may hide multiple lineages. Samples from across the geographic range of P. quadrilineata together with representatives from worldwide species with a focus on Atlantic d...
Article
Full-text available
The genus Bakawan includes species of haminoeid snails associated with mangrove habitats and mud flats in the Indo-West Pacific. Here, we revise the diversity and systematics of the genus Bakawan based on our recent molecular phylogeny (Oskars & Malaquias, 2019) and detailed analysis of morphological characters. We examined a range of morphological...
Preprint
Full-text available
Background: Heterobranchia is a diverse clade of marine, freshwater, and terrestrial gastropod molluscs. It includes such disparate taxa as nudibranchs, sea hares, bubble snails, pulmonate land snails and slugs, and a number of (mostly small-bodied) poorly known snails and slugs collectively referred to as the “lower heterobranchs.” Evolutionary re...
Preprint
Full-text available
Background Heterobranchia is a diverse clade of marine, freshwater, and terrestrial gastropod molluscs. It includes such disparate taxa as nudibranchs, sea hares, bubble snails, pulmonate land snails and slugs, and a number of (mostly small-bodied) poorly known snails and slugs collectively referred to as the “lower heterobranchs.” Evolutionary rel...
Preprint
Full-text available
Background Heterobranchia is a diverse clade of marine, freshwater, and terrestrial gastropod molluscs. It includes such disparate taxa as nudibranchs, sea hares, bubble snails, pulmonate land snails and slugs, and a number of (mostly small-bodied) poorly known snails and slugs collectively referred to as the “lower heterobranchs.” Evolutionary rel...
Article
The hermaphroditic marine snail species Haminella solitaria was formerly included in the genus Haminoea, but it was recently assigned to the genus Haminella. The copulatory apparatus in H. solitaria was investigated by light and transmission electron microscopy to obtain additional information about this apparatus in cephalaspidean gastropods and t...
Article
Full-text available
Runcinids are poorly known minute marine slugs inhabiting intertidal and shallow subtidal rocky shores. Among the European species, Runcina brenkoae, described from the Adriatic Sea in the Mediterranean, has been described to display chromatic variability, placing in question the true identity and geographic distribution of the species. In this pap...
Article
Full-text available
The genus Bakawan includes species of haminoeid snails associated with mangrove habitats and mud flats in the Indo-West Pacific. Here, we revise the diversity and systematics of the genus Bakawan based on our recent molecular phylogeny (Oskars & Malaquias, 2019) and detailed analysis of morphological characters. We examined a range of morphological...
Article
Full-text available
The cephalaspidean gastropod genus Haminoea has been considered a worldwide radiation with species living in intertidal and shallow areas with algae, seagrass sandy-mud, mangroves, and coral reefs. Recently this monophyletic status was questioned and it was suggested that Haminoea proper only included Atlantic plus eastern Pacific species, whereas...
Article
Full-text available
Since its introduction, the genus Philine has epitomized numerous mollusc snails with strong morphological convergence. Recently, a molecular analysis including a wide taxon sampling split this group into four non-sister families. Although they are especially diverse in cold and deep waters, no comprehensive studies are available for the Antarctic...
Article
Full-text available
Haminoeidae is the most diverse family of Cephalaspidea with 13 to 17 genera commonly recognised as valid and with 46 genera that historically have been moved back and forth between Haminoeidae and other families. Due to poor definition of most genera the family is plagued by extensive taxonomic confusion and its generic composition and internal re...
Article
Scaphander Montfort, 1810, is a genus of deep-sea soft-bottom gastropods composed of approximately 23 species distributed worldwide. The systematics of the genus in the Atlantic was recently revised and eight species were recognized. The present study describes a new species ( S. meridionalis sp. n.) from the Argentine continental slope using morph...
Article
Full-text available
Phanerophthalmus is a genus of Indo-West Pacific sea slugs inhabiting seagrass and coral reefs with up to now seven species currently recognised as valid. The goals of this study are to revise the systematics of Phanerophthalmus, infer its phylogeny and patterns of diversity, as well as study its diet. Morphology was combined with molecular phyloge...
Article
Full-text available
In this paper current knowledge on the diversity of the gastropod cephalaspidean genus Haminoea from India is revised. A comprehensive literature review was undertaken and novel specimens were collected. Specimens from India were DNA barcoded using the gene cytochrome c oxidase sub-unit I and a Bayesian gene tree together with an Automatic Barcode...
Article
Full-text available
Diniatys callosa (Preston, 1908) a new combination name for Haminoea callosa from the Andaman Islands (India).
Article
Molecular and morphological data from newly collected specimens and a review of the literature and type material indicate that the widespread tropical sea hare Dolabrifera dolabrifera is a species complex of five genetically distinct taxa. The name Dolabrifera dolabrifera is retained for a widespread species in the Indo-Pacific tropics. Dolabrifera...
Article
Antarctica has been hypothesized as a centre of origin of major heterobranch gastropod radiations, like Cephalaspidea and Nudipleura. Yet the study of Antarctic heterobranch diversity has been largely hampered by a lack of detailed morphological and anatomical studies, as well as comparative molecular phylogenetic approaches. Recently, the new ceph...
Article
Full-text available
Due to its biological and systematic importance, the morphology and function of the male copulatory apparatus of Haminoea navicula, a Cephalaspidea gastropod mollusk, was investigated by light and electron microscopy. These systems are poorly understood in haminoids, but are often used in the taxonomy of the genus. In H. navicula, the male copulato...
Article
Full-text available
Antarctica has been hypothesized as a centre of origin of major heterobranch gastropod radiations, like Cephalaspidea and Nudipleura. Yet the study of Antarctic heterobranch diversity has been largely hampered by a lack of detailed morphological and anatomical studies, as well as comparative molecular phylogenetic approaches. Recently, the new ceph...
Article
Full-text available
Molecular and morphological data from newly collected specimens and a review of the literature and type material indicate that the widespread tropical sea hare Dolabrifera dolabrifera is a species complex of five genetically distinct taxa. The name Dolabrifera dolabrifera is retained for a widespread species in the Indo-Pacific tropics. Dolabrifera...
Presentation
Full-text available
Abstract: Genome 60, 1010-1011. DOI: /10.1139/gen-2017-0178 Background: The University Museum of Bergen, Norway, has been cooperating with FAO’s EAF-Nansen-Project(http://www.fao.org/inaction/eaf-nansen/en) since 2005 in exploring benthic invertebrate diversity on the continental shelf of the Canary Current (CCLME) and Gulf of Guinea Large Marine...
Article
Full-text available
Aglajidae is a family of predominantly colourful shallow water marine slugs widely distributed in coral, rocky and sandy habitats of tropical and temperate waters worldwide. The monophyly of the group is supported by morphological traits, but recent molecular phylogenetic studies questioned not only the monophyletic status of the family but also th...
Article
Har du sett en geleaktig ball på omtrent en meter i diameter i sjøen? Hva er det egentlig for noe - eggkapsler fra blekksprut? Er dette et sjeldent syn, eller er det vanlig? Hvor finnes de, på hvilken tid av året kan man se dem, og på hvilket dyp?
Article
Full-text available
Atys jeffreysi is a heterobranch Cephalaspidea gastropod belonging to the family Haminoeidae occurring in the Mediterranean Sea, Madeira and Canary archipelagos. Nearly nothing is known about the internal anatomical features of this species. In this paper we redescribe the species A. jeffreysi based on fine anatomical work and scanning electron mic...
Article
Full-text available
In this reply, we address the criticism directed recently to our work (Malaquias et al. 2016) by Galil et al. (2016) dismissing the hypothesis that the Suez Canal can act as a revolving door allowing marine species to move both ways between the Red Sea and the Mediterranean Sea. We reiterate that the presence in the Red Sea of the Indo-West Pacific...
Article
Full-text available
The bubble snail Haminoea orteai Talavera, Murillo & Templado, 1987 has been reported from several localities in the Mediterranean and northeastern Atlantic. Although H. orteai can be easily recognized by having pigmented periocular areas, difficulties in the systematics of haminoeids hampered reliable identification of specimens. In addition, the...
Article
Full-text available
West Africa is often considered one of the least studied regions of the world concerning marine biodiversity. Knowledge about the philinid snails of the region has largely been based on shells, but shells can be insufficient to discriminate between species. In this paper, we review the diversity and revise the systematics of the West African specie...
Article
Traditionally, species identification in nudibranch gastropods relies heavily on body color pattern. The Felimida clenchi species complex, a group of brightly colored Atlantic and Mediterranean species in the family Chromodorididae, has a history of exceptional controversy and discussion among taxonomists. The most widely accepted hypothesis is tha...
Article
Full-text available
The eastern Atlantic and Mediterranean marine Cephalaspidea gastropod Haminoea orbignyana was collected from Lake Qarun (Fayoum, Egypt), a landlocked lake that has undergone a shift from freshwater to estuarine conditions in the past 100 years. Species identity was confirmed by both morphological (anatomical dissection and scanning electron microsc...
Data
Growth of Haminoea over 16 days. (XLSX)
Data
Haminoea individuals and egg mass abundance. (XLSX)
Data
Feeding of Haminoea in no-choice experiment. (XLSX)