Four Decades of Overlooked Data Reveal the Hidden Amphipod Diversity of Italian Seas

A new inventory of over 300 amphipod species from Italian seas offers an updated picture of their distribution and biodiversity.

Guest blog post by Prof. Sabrina Lo Brutto

What if some of the most important clues about marine biodiversity were already collected but never fully shared?

That’s the question that motivated this study, published in Biodiversity Data Journal. It brought together over 40 years of unpublished data on marine amphipods – ecologically crucial crustaceans – from across Italian waters. By unifying scattered records and making them openly accessible, researchers have assembled comprehensive and up-to-date inventories of these species for the Mediterranean.

Satellite image of the  Mediterranean Sea with Italy and Sicily.
Satellite image of the Mediterranean Sea with Italy and Sicily. Image provided by Prof. Sabrina Lo Brutto.

Researchers analysed 4,344 previously unpublished records spanning from 1980 to 2025, identifying 302 amphipod species across the Adriatic, Tyrrhenian, and Ionian Seas. Interestingly, they found that the Tyrrhenian Sea harbours the highest taxonomic richness (258 species), while the Adriatic Sea accounts for the greatest number of records due to intense historical sampling.

A Number of species per sea; B Venn diagram illustrating the distribution and shared amphipod species across the three areas, Tyrrhenian Sea (light blue), Ionian Sea (red), Adriatic Sea (blue). Credit to Badalucco et al., 2026.

This work not only updates the Italian inventory but also reinforces the country’s central role as a biodiversity hotspot in the Mediterranean.

noted Prof. Sabrina Lo Brutto of the Department of Earth and Sea Sciences (DiSTeM) at the University of Palermo, the coordinator of the study. 

Why amphipods matter

A female hyalid amphipod species (Serejohyale sicilia) with eggs
A female hyalid amphipod species (Serejohyale sicilia) with eggs. Image credit to Prof. Sabrina Lo Brutto.

Amphipods are small, often just a few millimeters long, but they play an outsized role in marine ecosystems. They recycle nutrients, connect food webs, and serve as prey for fish, birds, and mammals. Because they respond quickly to environmental stress, they are also powerful bioindicators, helping scientists detect pollution and ecological changes.

Yet despite their importance, our knowledge of where these species live has been fragmented. In some cases, outdated or incomplete records have even led to cascading misidentifications in the scientific literature.

A collaborative effort across Italy

Map of Italy with georeferenced species records
Map showing the distribution of the georeferenced species records. Points were differentiated by colours, based on the sea upon which they lie: Tyrrhenian Sea (light blue), Ionian Sea (red) and Adriatic Sea (blue). Credit to Badalucco et al., 2026.

This study represents a collective effort coordinated under the National Biodiversity Future Center (NBFC). Researchers from universities, environmental agencies, and research institutes across Italy contributed data spanning more than four decades.

By harmonizing these datasets under the FAIR principles (Findable, Accessible, Interoperable, Reusable), we ensured that the information was not only scientifically robust but also openly available for future research.

commented the first author of the study, Dr. Antonina Badalucco (Dept. DiSTeM, University of Palermo).

The full dataset is now accessible via the Global Biodiversity Information Facility (GBIF), making it a resource for scientists worldwide.

A changing Mediterranean

Percentage of the amphipod species per substrate/habitat categories.
*The species Dendropoma petraeum is now accepted as Dendropoma cristatum. Credit to Badalucco et al., 2026.

The presence of non-indigenous species is a reminder that marine ecosystems are rapidly evolving. The study identified 11 alien species primarily concentrated in ports, lagoons such as the Venice Lagoon, and aquaculture facilities. Increased shipping, aquaculture, and global connectivity are allowing these species to travel farther and establish themselves in new environments, sometimes with significant ecological consequences.

At the same time, researchers observed that sampling efforts have intensified dramatically in the last decade, driven in part by European environmental policies such as the Marine Strategy Framework Directive – generating a surge in available data, while also highlighting how much earlier information had remained underused.

Why this matters now

Understanding where species live is the foundation of conservation. Without accurate distribution data, it’s nearly impossible to track biodiversity loss, identify vulnerable habitats, or design effective protection strategies.

Prof. Lo Brutto explained

By filling long-standing gaps in knowledge, this research supports broader efforts – such as the EU’s and National Biodiversity Future Centre’s shared goal to protect 30% of land and sea by 2030 – and provides a baseline for monitoring future environmental change.

Looking ahead

This is not the end of the story; it’s a starting point. Our study shows the immense value of unlocking existing data and making it accessible. We hope it will inspire similar efforts across other regions and taxonomic groups, helping to build a more complete picture of life in our oceans.

Prof. Lo Brutto concluded

Original study:

Badalucco A, Auriemma R, Balistreri P, Baratti M, Bonifazi A, Capillo G, Cimmaruta R, Coccia I, D’Amore A, Desiderato A, D’Iglio C, Grech D, Iaciofano D, Lattanzi L, Lezzi M, Lionello M, Macaluso E, Mancini E, Martino C, Marusso V, Mercurio M, Mucciolo S, Prato E, Pulieri M, Puthod P, Scipione MB, Scirocco T, Sirchia B, Specchiulli A, Targusi M, Trabucco B, Vannucci A, Rosati I, Lo Brutto S (2026) A contribution to the inventory of marine amphipod species from Italian waters based on unpublished sources and FAIR principles. Biodiversity Data Journal 14: e189256. https://doi.org/10.3897/BDJ.14.e189256

Scientists dive into museum collections to reveal the invasion route of a small crustacean

Biological invasions are widely recognised as one of the most significant components of global change. Far-reaching and fast-spreading, they often have harmful effects on biodiversity.

Therefore, acquiring knowledge of potentially invasive non-native species is crucial in current research. In particular, it is important that we enhance our understanding of the impact of such invasions.

To do so, Prof Sabrina Lo Brutto and Dr Davide Iaciofano, both working at the Taxonomy Laboratory of the University of Palermo, Italy, performed research on an invasive alien crustacean (Ptilohyale littoralis) known to have colonised the Atlantic European Coast. Their findings are published in the open access journal ZooKeys.

The studied species belongs to a group of small-sized crustaceans known as amphipods. These creatures range from 1 to 340 mm in length and feed on available organic matter, such as dead animals and plants. Being widely distributed across aquatic environments, amphipods have already been proven as excellent indicators of ecosystem health.

While notable for their adaptability and ecological plasticity, which secure their abundance in various habitats, these features also make amphipods especially dangerous when it comes to playing the role of invaders.

Having analysed specimens stored at the Museum of Natural History of Verona and the Natural History Museum in Paris, the scientists concluded that the species has colonised European waters 24 years prior to the currently available records.

The problem was that, back in 1985, when the amphipod was first collected from European coasts, it was misidentified as a species new to science instead of an invader native to the North American Atlantic coast.

A closer look into misidentified specimens stored in museum collections revealed that the species has been successfully spreading along the European coastlines.

Male of the invasive amphipod species (Ptilohyale littoralis), sampled in October 2015, from Bay of Arcachon, France.

Moreover, it was predicted that the amphipod could soon reach the Mediterranean due to the high connectivity between the sea and the eastern Atlantic Ocean through the Straits of Gibraltar – a route already used by invasive marine fauna in the past.

In the event that the invader reaches the Mediterranean, it is highly likely for the crustacean to meet and compete with a closely related “sister species” endemic to the region. To make matters worse, the two amphipods are difficult to distinguish due to their appearance and behaviour both being extremely similar.

However, in their paper, the scientists have also provided additional information on how to distinguish the two amphipods – knowledge which could be essential for the management of the invader and its further spread.

The authors believe that their study demonstrates the importance of taxonomy – the study of organism classification – and the role of natural history collections and museums.

“Studying and monitoring biodiversity can acquire great importance in European aquatic ecosystems and coastal Mediterranean areas, where biodiversity is changing due to climate change and invasions of alien species,” Prof Lo Brutto says. “In this context, specific animal groups play a crucial role in detecting such changes and they, therefore, deserve more attention as fundamental tools in biodiversity monitoring.”

“Regrettably, the steadily diminishing pool of experts capable of accurately identifying species poses a serious threat in this field.”

###

Original source:

Lo Brutto S, Iaciofano D (2018) A taxonomic revision helps to clarify differences between the Atlantic invasive Ptilohyale littoralis and the Mediterranean endemic Parhyale plumicornis(Crustacea: Amphipoda). ZooKeys, 754: 47-62. https://doi.org/10.3897/zookeys.754.22884

Life in marine driftwood: The case of driftwood specialist talitrids

Driftwood in the sea – either floating or stranded on beaches – is a common feature particularly in temperate regions. Large quantities of driftwood, termed driftwood depositories, may collect at the mouth of small streams associated with marshes and have been present for some 120 millennia – since the origin of flowering plants.

Once marine driftwood begins to decay, it undergoes a specific succession. Firstly, it is colonized by salt tolerant, wood degrading fungi and bacteria, along with a few invertebrates able to digest wood by producing native wood degrading enzymes. The latter include gribbles (isopods) and chelurid amphipods.

Driftwood hoppers (talitrids), as well as isopods, chilopods, insect larvae, some ants and termites, comprize the secondary colonizers. They are all characterized by their inability to utilize driftwood directly. Instead, they rely on symbiotic microflora for digestive purposes.

Within all talitrids, the driftwood hoppers count as few as seven species, most likely because they are extremely difficult to locate and, therefore, discover and describe. Apart from living in tiny burrows, they measure between 13 and <6 mm, which makes the latter the smallest known talitrid.

Having reviewed the driftwood specialized talitrids, Dr. David Wildish of the St. Andrews Biological Station, Canada, concludes that all seven known species demonstrate dwarfism based on slow metabolism and growth. Their sexual development begins earlier compared to faster growing related species. All of them are also characterized with reduced eye size and absence of dorsal pigment patterns.

In his review article published in the open access journal Zoosystematics and Evolution, the scientist confirms that dwarfism in driftwood hoppers has evolved due to poor diet, in turn resulting in slowed metabolism and growth. A further adaptive challenge is the empty gribble burrow size occupied by talitrids (burrow diameter between 0.6 to 5 mm) with the smaller ones being more widespread. Larger talitrids can only complete their life cycle in the larger burrows.

“The size gradient in gribble burrow diameter provides a satisfactory explanation for serial dwarfism within the driftwood talitrids and is why each species becomes successively smaller,” explains the researcher.

Responsibility for first establishing the driftwood talitrid ecological grouping was made during graduate studies by David Wildish, London University, U.K., and Laura Pavesi, University of Rome, Italy. The two criteria for inclusion of a talitrid in the driftwood grouping was: behavioral fidelity to the occupied driftwood and that the food source was solely rotting driftwood (see references).

The larger talitrid family are small/medium in body length (< 30 mm) crustaceans with more than 400 species described in the world list. Ecological groupings within the family include marine/estuarine supralittoral wrack generalists, sand-burrowing, marsh-living and driftwood specialists. A few freshwater and many terrestrial species are also known.

###

Original source:

Wildish DJ (2017) Evolutionary ecology of driftwood talitrids: a review. Zoosystematics and Evolution 93(2): 353-361. https://doi.org/10.3897/zse.93.12582