The study grew out of a Master’s thesis by Hannes Bonhoff, who recently completed his degree in biology at Lund University, and was co-authored with Heikki Helanterä, professor of evolutionary biology and genomics at the University of Oulu. Their starting point was a conceptual one: what does it actually mean, biologically, for a colony to be a single organism rather than a society of many? The superorganism idea has circulated in biology for more than a century, but the authors argue that it has rarely been worked through in a genuinely biological context for honey bees. By taking the concept seriously, they say, previously familiar features of colony life fall into a new and revealing pattern.

The most striking of these patterns concerns the life cycle. Bonhoff likens the colony to an individual mammal that passes through gestation and extensive parental care. Every generation of a honey bee colony, he notes, develops from a single bee — the queen — and progresses through stages that parallel those of a mammal: embryo, foetus, juvenile, and adult. The comparison extends to mortality. Just as an individual animal ages, the colony as a superorganism undergoes an inevitable biological ageing process, which means that a colony dies after only a few years. In this framing, the death of a colony is not a failure of management but a normal stage in the life history of a single, long-lived organism.

Reproduction is where the analogy becomes most vivid. Honey bees reproduce by swarming: the queen and roughly half of the colony’s workers fly off together to find a new hive, while a newly raised queen remains in the old nest to found the next generation. Viewed through the superorganism lens, this is parental care of an extraordinary kind. The offspring colony inherits the mother’s nest — a fully built, climate-controlled structure stocked with food — while the parent organism risks its life by flying away to settle elsewhere. “When this superorganism reproduces, the offspring are cared for with great dedication by the parent, in some cases even at the cost of the parent’s life,” Bonhoff says.

The care does not end with real estate. The developing offspring colony matures inside the safety of its mother colony, supplied with food, shelter, and a well-constructed hive. The mother colony also transmits knowledge. Young bees learn the species’ famous dance language, the symbolic communication system used to direct nestmates to flowers, and the parent colony guides the new generation toward the most nutritious foraging sites. In biological terms, the researchers describe a form of cultural and nutritional provisioning that parallels the extended parental investment seen in mammals and birds, here spread across thousands of individual workers acting, functionally, as the organs of a single body.

Niklas Wahlberg, professor of systematic biology at Lund University and one of Bonhoff’s thesis supervisors alongside Helanterä, finds the reframing valuable precisely because it gives the superorganism concept concrete biological content. “The concept itself has been around for a long time, but this is the first time it has been applied in a genuine biological context,” he says. “It’s fascinating to think that, just as individual cells make up an organism, individual bees with different roles make up the superorganism.” His comment underscores the intellectual appeal of the paper: it takes a term that has often served as an evocative analogy and asks what follows if it is treated as a literal description of the colony’s biology.

The practical stakes emerge when the framework is applied to modern beekeeping. Contemporary management, the authors argue, is built on the assumption that a colony can be kept young and healthy indefinitely. Two of the most widespread interventions — the forced replacement of queens and the artificial prevention of swarming — are designed precisely to interrupt the colony’s natural life cycle, suppressing reproduction and resetting the superorganism’s biological clock. Bonhoff’s analysis suggests that these practices do not merely inconvenience the bees; they fundamentally conflict with the colony’s natural reproductive strategy and, in doing so, may undermine its ability to cope with disease.

The most urgent example is the Varroa mite, a parasitic arachnid that preys on honey bees worldwide and is widely regarded as one of the greatest threats to managed pollination. Because the superorganism framework ties colony health to the natural life history — including swarming, which naturally breaks the reproductive cycle of parasites within a nest — Bonhoff argues that understanding colonies as single organisms offers crucial insights into how to deal with such parasites. A shift in perspective, he suggests, is valuable for the global beekeeping community as it works to safeguard this essential pollinator, pointing toward more sustainable and animal-friendly methods rather than indefinite artificial rejuvenation.

“We have analysed what it means for a bee colony to be a single organism, which opens up new insights into the fascinating life of the honey bee,” Bonhoff says. Whether the field adopts the superorganism as a working biological category or treats it as a productive heuristic, the study makes a clear case that the choice is not cosmetic. If a colony is an individual — developing, ageing, reproducing, and dying on its own schedule — then every management decision that interrupts that schedule becomes a biological intervention with consequences that beekeepers have not fully accounted for. For an animal on which much of the world’s food production depends, that reframing may prove to be more than a philosophical exercise.

Subject of Research: The honey bee colony as a superorganism and its implications for beekeeping

Article Title: A honey bee colony can be viewed as a superorganism

Article References: A honey bee colony can be viewed as a superorganism. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: honey bees, superorganism, colony biology, swarming, Varroa mite, beekeeping, parental care, life history, Insectes Sociaux, Lund University, evolutionary biology, pollinators

Alternative reproductive tactics, known in the literature as ARTs, are among the most striking manifestations of sexual selection. Instead of every male competing on the same terms, populations evolve two or more discrete behavioural or morphological strategies within one sex. In countless species, from salmon to dung beetles to frogs, large ‘bourgeois’ males guard territories, court females and care for offspring, while smaller ‘sneaker’ or ‘parasitic’ males forgo courtship entirely, darting into rival nests to release sperm at the decisive moment. The payoff for each tactic is frequency dependent:bourgeois males do well while they are rare, sneakers thrive when they can slip past the guards. Although ARTs have been documented across most major animal groups, their evolution in freshwater fishes remains poorly understood, and within the Gobiidae, the goby family, the evidence has been remarkably thin.

That gap mattered to the researchers behind the new study because gobies are no minor sideshow. The family comprises roughly 2,000 species across 212 genera, making it one of the most species-abundant vertebrate families on Earth. Most gobies are small, typically under 15 centimetres, and are distinguished by fused pelvic fins that form an adhesive disc. Many exhibit substrate-associated spawning, with males guarding nests of developing eggs, a breeding system that in other goby lineages has repeatedly spawned sneaker tactics. South African freshwater gobies, which occur naturally along the eastern seaboard from northern Mozambique to the Cape region, are believed to share this nest-guarding habit, but their mating systems had never been examined in detail. The River Goby, an important component of freshwater fish assemblages in Southern African rivers, was an ideal candidate for a closer look.

The study focused on a population living in ten man-made ponds in the semi-arid Lower Sundays River Valley of the Eastern Cape Province. Between winter 2013 and autumn 2015, the team sampled fish seasonally using a 30-metre seine net, measuring total length to the nearest tenth of a millimetre and wet body weight to the nearest tenth of a gram. In the laboratory, specimens were dissected, gonads were assessed against a standard five-stage maturity classification, and reproductive investment was quantified using the gonadosomatic index, or GSI, the ratio of gonad mass to eviscerated body mass expressed as a percentage. The work was ethically approved by the NRF-South African Institute for Aquatic Biodiversity Animal Ethics Committee, with specimens collected under permits from the Eastern Cape provincial authorities.

One of the study’s most practical contributions is a simple, non-lethal method for sexing these fish. Examination of the urogenital papilla, a small external structure, proved completely reliable: females possess broader, blunt papillae, while males have shorter, pointed ones. Chi-square analysis confirmed that every one of the 392 individuals identified as male externally was verified as male by gonadal dissection, and all 399 individuals with the female-type papilla were confirmed as females, a 100 percent accuracy rate. Because live-bearing-free sexing usually requires sacrificing and dissecting fish, a validated external marker opens the door to behavioural and longitudinal studies that would otherwise be impossible on a species whose reproductive tactics are still being pieced together.

The sex ratio of the sampled population itself carried a signal: 392 males, 399 females and 37 juveniles produced a female-dominated ratio of 1 male to 1.21 females, a significant departure from parity. But the headline finding lay in the males. Based on pelvic fin coloration, the team identified three morphologically distinct morphs. Dark-morph males, displaying deep pigmentation, were significantly longer and heavier than light-morph males, while intermediate males fell between the extremes. Among the 98 reproductively ripe males captured, light morphs were the most common, followed by intermediates and then dark males, a distribution that foreshadowed the functional differences the analysis would later expose.

The decisive evidence came from the pattern of gonadal investment across body sizes. A loess regression of GSI against total length revealed sharp discontinuities between the morphs. Light-morph males showed elevated gonadosomatic indices at small body sizes, in the 70 to 85 millimetre range, while dark-morph males achieved peak GSI only at larger sizes, between 95 and 105 millimetres. In evolutionary terms, this is the classic signature of a trade-off. Small males that cannot win territory or attract mates appear to channel a disproportionate share of their energy into testes development, priming themselves for sperm competition inside another male’s nest, while large, dark, presumably territorial males invest in size and dominance displays rather than sheer gonadal output. Light morphs were, in fact, heavier than medium morphs, further hinting that the intermediate form is not simply a scaling of the same strategy.

Seasonal abundance data added a temporal dimension. Dark morphs peaked in spring, with 355 individuals recorded, and summer, with 202 individuals, a window that corresponds precisely to the known reproductive season of the species in the Sundays River system, which runs from early spring in September to mid-summer in December. Light morphs, by contrast, were most abundant in winter, with 142 individuals recorded outside the breeding season. The authors interpret this as evidence that the morphological and physiological traits underpinning sneaker tactics are established before the breeding season begins, allowing pale males to be ready to exploit spawning opportunities the moment they arise. Such preparation is consistent with the idea that reproductive tactics are not improvised at the nest but develop over months in anticipation of competition.

The parallels with other gobies are striking and suggest convergent forces at work. In the invasive Round Goby, Neogobius melanostomus, researchers have documented ontogenetically distinct tactics in which small males adopt sneaker behaviour with higher relative gonadal investment while larger males defend territories and provide parental care. In Caspian gobies, three male types, large territorial courters, intermediates and small cuckolding parasites, have been described in multiple species. The recurring appearance of this tripartite system across geographically separate gobiid lineages points to strong and consistent selective pressures, most likely intense male-male competition for limited spawning sites in a family where nest-guarding males effectively monopolize reproduction. Whether the same pressures shaped the Sundays River population remains an open question, but the morphological fingerprints are remarkably consistent.

Important caveats remain, and the authors are careful to flag them. Direct behavioural observations of spawning have not yet been conducted for G. callidus, so the assignment of tactics to morphs rests on morphological and physiological evidence rather than on watching dark males guard nests or light males dart into them. It is also unknown whether the morphs represent fixed genetic strategies or condition-dependent plastic responses, with individual males potentially switching tactics as they grow, as has been suggested for condition-dependent tactics in other gobies. Phenotypic plasticity allows genotypic expression to vary with environmental conditions, and life-history theory holds that reproductive traits evolve through trade-offs in which the evolution of one trait constrains or influences another. Genetic analyses, sperm quality assessments across morphs and direct observations of spawning competition are the logical next steps, along with determining whether the intermediate morph is a transitional stage en route from sneaker to parental or a distinct tactic in its own right. Whatever the answers, the study delivers the first evidence of alternative reproductive tactics in this endemic Southern African goby, and it underscores a broader lesson for freshwater ecology: beneath the surface of even the humblest pond fish, evolution may be running several different games at once, each with its own winners, losers and rules of engagement.

Subject of Research: Alternative reproductive tactics in the River Goby Glossogobius callidus

Article Title: Alternative reproductive tactics and strategies of Glossogobius callidus (Teleostei: Gobiidae)

Article References: Cembi, O., Mutshekwa, T., Munyai, L. F., Ndaleni, P., & Mofu, L. (2026). Alternative reproductive tactics and strategies of Glossogobius callidus (Teleostei: Gobiidae). Discover Ecology, 2(1), Article 3. https://doi.org/10.1007/s44396-025-00021-w

Image Credits: AI Generated

DOI: 10.1007/s44396-025-00021-w

Keywords: alternative reproductive tactics, River Goby, Glossogobius callidus, Gobiidae, sneaker males, parental care, sexual selection, gonadosomatic index, South Africa, freshwater fish, pelvic fin coloration, reproductive strategies

The research team, led by Daniel Antonio Ortega-Rosas of the Instituto de Ecología A.C. together with colleagues from the Instituto Politécnico Nacional, set out to test whether the benefits of parental care go beyond the microbial transfer from parents to brood balls that earlier studies had proposed. Their hypothesis was that the physical maintenance of the brood ball itself—the moisture it retains, its acidity, and its structural consistency—might be just as important as any microbial inheritance. To investigate, they designed a controlled experiment that manipulated both the presence of parents and the humidity of the surrounding environment, creating a factorial matrix of conditions under which brood balls and their developing larvae could be observed.

The experiment exposed brood balls, some tended by parents and some left alone, to four levels of relative humidity: 30 percent, 50 percent, 65 percent, and 70 percent. At each level, the researchers measured the gravimetric water content of the brood balls, their pH, and their hardness, while simultaneously tracking larval survival and developmental progress. The design allowed the team to disentangle the effects of parental behavior from those of ambient moisture, a distinction that previous work had not clearly established.

The results were striking. Parental care significantly contributed to maintaining both the moisture and the structural integrity of brood balls, but these benefits were strongly dependent on the ambient relative humidity. High humidity of at least 65 percent emerged as a critical threshold for larval survival and for progression to advanced developmental stages, and this was true regardless of whether parents were present. At the other end of the spectrum, when relative humidity dropped to 50 percent or below, larval mortality reached a devastating 100 percent, even when parents remained in attendance. In other words, parental care could not rescue offspring from an environment that was simply too dry.

This finding reframes our understanding of what parental care actually does for these beetles. Rather than acting primarily as a shield against fungal infection through microbial transfer, as had been suggested, the parents’ most vital contribution appears to be preventing brood ball desiccation. A brood ball that retains its moisture preserves a crucial physical property: structural plasticity. The developing larva must be able to migrate through the ball to reach the food chamber where it feeds, and a hardened, dried-out ball turns this journey into an impassable obstacle. By keeping the ball pliable, parents ensure that their offspring can physically access the resources they need to grow.

Beyond moisture, the researchers found that parental care produced a slightly more alkaline pH in the brood balls across most treatments. While this shift might seem subtle, pH is a fundamental driver of microbial ecology, and the change appeared to be associated with measurable differences in the bacterial communities colonizing the brood ball surface. To characterize these communities, the team employed metataxonomic analysis of the 16S ribosomal RNA gene, sequencing the V3–V4 region to identify the bacteria present under each experimental condition.

The microbiome results added a rich new dimension to the story. Parental care significantly influenced the bacterial assemblage on the brood ball surface, increasing alpha diversity and favoring genera associated with organic matter degradation and antimicrobial activity. Among the genera enriched in the presence of parents were Nocardioides, known for its ability to break down complex pollutants; Bacillus, a genus famous for producing antimicrobial compounds; and Nannocystis, a myxobacterium with documented bioactivity. These taxa suggest that caring parents are not merely keeping their nests damp but are actively cultivating a microbial community that may help suppress harmful fungi and accelerate the decomposition processes that make the brood ball’s contents digestible for the larva.

Equally intriguing was the discovery of a bacterial core shared across all brood balls regardless of treatment. Eight genera, including Acinetobacter, Sphingobacterium, and Micromonospora, were consistently present, forming a baseline microbiome that appears to be a stable feature of the brood ball environment. The presence of Micromonospora is particularly noteworthy, as members of this genus are renowned producers of bioactive natural products and have been isolated from diverse insect systems, where they may contribute to host defense. The combination of a consistent core community with parentally enhanced diversity suggests a layered system: a foundational microbiome that comes with the brood ball, overlaid by parental modifications that tip the ecological balance toward microbes beneficial to offspring.

The implications of this work extend beyond the biology of a single beetle species. Dung beetles and their necrophagous relatives are keystone decomposers in tropical ecosystems, responsible for nutrient cycling, soil aeration, and secondary seed dispersal. Canthon cyanellus cyanellus, as a subsocial species that invests heavily in each brood ball, may be especially vulnerable to environmental perturbations that disrupt its delicate reproductive calculus. The study’s authors point out that shifts toward drier conditions, whether driven by climate change or deforestation, could significantly compromise the reproductive success of this species. If ambient humidity falls below the critical threshold of roughly 65 percent, no amount of parental diligence can save the brood, meaning that habitat drying translates directly into reproductive failure.

This research also speaks to a broader question in evolutionary biology: why has subsocial behavior, in which parents remain with offspring long after egg-laying, evolved repeatedly in scarabaeine beetles? The answer emerging from this study is that parental care in these insects functions through multiple synergistic channels. It is at once a hydraulic engineering project, maintaining the moisture that keeps the nursery habitable; a microbiological stewardship program, enriching the bacterial community with degradative and antimicrobial taxa; and a modest chemical intervention, shifting brood ball pH toward conditions that may favor beneficial microbes. The convergence of these mechanisms explains why parental presence so dramatically improves offspring outcomes under suitable humidity, and why it becomes powerless when the environment itself turns hostile. As tropical forests warm and dry, understanding these finely tuned dependencies becomes essential for predicting which species will persist and which will quietly disappear, one failed brood ball at a time.

Subject of Research: Parental care effects on brood ball physicochemical properties and bacterial communities in the subsocial dung beetle Canthon cyanellus cyanellus

Article Title: Parental care in Canthon cyanellus cyanellus maintains brood ball moisture and shapes bacterial communities: implications for offspring survival

Article References: Parental care in Canthon cyanellus cyanellus maintains brood ball moisture and shapes bacterial communities: implications for offspring survival. (n.d.). https://doi.org/10.1007/s00114-026-02160-w

Image Credits: AI Generated

DOI: 10.1007/s00114-026-02160-w

Keywords: Canthon cyanellus cyanellus, parental care, brood balls, relative humidity, larval survival, bacterial communities, metataxonomy, dung beetles, subsocial behavior, microbiome, desiccation, climate change